[Thermodynamics] Reversible process And Factor causing internal irreversibility

                   Reversible Process And Factors Causing Internal Irreversibility 



A process is said to be reversible when there are no dissipative effects, all the work done by the syste during the performance of a process in one direction can be returned to the system during the reverse process.


A process will be reversible when it is performed in such a way that the system is all time infinitesimally near a state of thermodynamic equilibrium and in the absence of dissipative effect of any form.


the internal irreversibility is caused by the internal dissipative effects like friction, turbulence, electrical resistance, magnetic hyteresis etc within the system.  

[Thermodynamics] Thermodynamic Equilibrium

                                             Thermodynamic Equilibrium


A system which is simultaneously in a state of mechanical equilibrium, thermal equilibrium and chemical equilibrium is said to be in a state of thermodynamic equilibrium.

When there is no unbalanced force with in the system and it's boundaries, then the system is said to be in mechanical equilibrium.

when there is no change in internal structure due to chemical reactions or diffusion then the system is said to be in chemical equilibrium.

when there is uniformity in temperature then there is thermal equilibrium of the system.

[ Fun Facts] Some Interesting Fun Facts

                           SOME OF THE INTERESTING FUN FACTS

1. Banging your head against a wall burns 150 calories an hour.
2. In the UK, it is illegal to eat mince pies on Christmas Day!
3. Pteronophobia is the fear of being tickled by feathers!
4. When hippos are upset, their sweat turns red.
5. A flock of crows is known as a murder.
6. “Facebook Addiction Disorder” is a mental disorder identified by Psychologists.
7. The average woman uses her height in lipstick every 5 years.
8. 29th May is officially "Put a pillow on your fridge day".
9. Cherophobia is the fear of fun.
10. Human saliva has a boiling point three times that of regular water.
11. If you lift a kangaroo's tail off the ground it can’t hop.
12. Hyphephilia are people who get aroused by touching fabrics.
13. Billy goats urinate on their own heads to smell more attractive to females.
14. The person who invented the Frisbee was cremated and made into frisbees after he died!
15. During your lifetime, you will produce enough saliva to fill two swimming pools.
16. An eagle can kill a young deer and fly away with it.
17. Polar bears can eat as many as 86 penguins in a single sitting.
18. King Henry VIII slept with a gigantic axe beside him.
19. Bikinis and tampons invented by men.
20. If Pinokio says “My Noes Will Grow Now”, it would cause a paradox. 
21. Heart attacks are more likely to happen on a Monday.
22. If you consistently fart for 6 years & 9 months, enough gas is produced to create the energy of an atomic bomb!
23. An average person’s yearly fast food intake will contain 12 pubic hairs.
24. The top six foods that make your fart are beans, corn, bell peppers, cauliflower, cabbage and milk!
25. There is a species of spider called the Hobo Spider.
26. ‘Penis Fencing’ is a scientific term for the mating ritual between flatworms. It involves two flatworms attempting to stab the other flatworm with their penis.
27. A toaster uses almost half as much energy as a full-sized oven.
28. A baby spider is called a spiderling.
29. You cannot snore and dream at the same time.
30. The following can be read forward and backwards: Do geese see God?
31. A baby octopus is about the size of a flea when it is born.
32. A sheep, a duck and a rooster were the first passengers in a hot air balloon.
33. In Uganda, 50% of the population is under 15 years of age.
34. Hitler’s mother considered abortion but the doctor persuaded her to keep the baby.
35. Arab women can initiate a divorce if their husbands don’t pour coffee for them.
36. Recycling one glass jar saves enough energy to watch TV for 3 hours.
37. Smearing a small amount of dog feces on an insect bite will relieve the itching and swelling.
38. Catfish are the only animals that naturally have an odd number of whiskers.
39. Facebook, Skype and Twitter are all banned in China.
40. 95% of people text things they could never say in person.
41. The Titanic was the first ship to use the SOS signal.
42. In Poole, ‘Pound World’ went out of business because of a store across the road called ’99p Stores’, which was selling the same products but for just 1 pence cheaper! 
43. About 8,000 Americans are injured by musical instruments each year.
44. The French language has seventeen different words for ‘surrender’.
45. Nearly three percent of the ice in Antarctic glaciers is penguin urine.
46. Bob Dylan’s real name is Robert Zimmerman.
47. A crocodile can’t poke its tongue out :p
48. Sea otters hold hands when they sleep so they don’t drift away from each other.
49. A small child could swim through the veins of a blue whale.
50. Bin Laden’s death was announced on 1st May 2011. Hitler’s death was announced on 1st May 1945.
51. J.K. Rowling chose the unusual name ‘Hermione’ so young girls wouldn’t be teased for being nerdy!
52. Hewlett-Packard’s name was decided in a coin toss.
53. The total number of steps in the Eiffel Tower are 1665.
54. The Pokémon Hitmonlee and Hitmonchan are based off of Bruce Lee and Jackie Chan.
55. The toothpaste ‘Colgate’ in Spanish translates to ‘go hang yourself’. 
56. Pirates wore earrings because they believed it improved their eyesight.
57. Los Angeles’s full name is “El Pueblo de Nuestra Senora la Reina de los Angeles de Porciuncula.”
58. Dr. Kellogg introduced Kellogg Corn Flakes in hopes that it would reduce masturbation.
59. The testicles on an octopus are located in its head!
60. In England, in the 1880’s, “Pants” was considered a dirty word.
61. It snowed in the Sahara desert for 30 minutes on the 18th February 1979.
62. Every human spent about half an hour as a single cell.
63. If you leave everything to the last minute… it will only take a minute.
64. Ithyphallophobia is the fear of erections.
65. The first alarm clock could only ring at 4am.
66. Birds don’t urinate.
67. Dying is illegal in the Houses of Parliaments – This has been voted as the most ridiculous law by the British citizens.
68. The word ‘ejaculation’ comes from the Latin word meaning ‘throwing out’.
69. The 20th of March is known as Snowman Burning Day!
70. Slugs have 4 noses.
71. Panphobia is the fear of everything… which is a pretty unlucky phobia to have.
72. An apple, potato, and onion all taste the same if you eat them with your nose plugged.
73. George Washington grew marijuana in his garden.
74. A company in Taiwan makes dinnerware out of wheat, so you can eat your plate!
75. The average person walks the equivalent of twice around the world in a lifetime.
76. The Bible is the most shoplifted book in the world.
77. Macro Hort has the world record for fitting 264 straws in his mouth at once!
78. Mel Blanc – the voice of Bugs Bunny – was allergic to carrots.
79. California has issued 6 drivers licenses to people named Jesus Christ.
80. According to Genesis 1:20-22 the chicken came before the egg.
81. In the Caribbean there are oysters that can climb trees.
82. Worms eat their own poo.
83. Squirrels forget where they hide about half of their nuts.
84. Over 1000 birds a year die from smashing into windows.
85. The inventor of the Waffle Iron did not like waffles.
86. George W. Bush was once a cheerleader.
87. In Japan, it is completely acceptable to name your child ‘Buttocks’ or ‘Prostitute’.
88. In 1895 Hampshire police handed out the first ever speeding ticket, fining a man for doing 6mph!
89. Each year, there are more than 40,000 toilet related injuries in the United States.
90. A tapir has the largest penis-to-body ratio of any animal.
91. Mewtwo is a clone of the Pokémon Mew, yet it comes before Mew in the Pokédex.
92. Every year more than 2500 left-handed people are killed from using right-handed products.
93. Madonna suffers from garophobia which is the fear of thunder.
94. China has more English speakers than the United States.
95. Samuel L. Jackson requested to have a purple light saber in Star Wars in order for him to accept the part as Mace windu.
96. Paraskavedekatriaphobia is the fear of Friday the 13th!
97. Kleenex tissues were originally used as filters in gas masks.
98. In 1998, Sony accidentally sold 700,000 camcorders that had the technology to see through people’s clothes. These cameras had special lenses that use infrared light, which allowed you to see through some types of clothing.
99. Upon losing battles, apes will tend to masturbate.
100. Ronald McDonald is “Donald McDonald” in Japan because it makes pronunciation easier for the Japanese. In Singapore he’s known as “Uncle McDonald”.

[Thermodynamics] The reason why carnot cycle not practicable for a steam power plant

           WHY CARNOT CYCLE IS NOT PRACTICABLE FOR A STEAM POWER PLANT


Theoretically, a carnot cycle is most efficient, however, the following difficulties are associated with it when steam is the working fluid.

• Steam condensation is not allowed to proceed to completion. The condensation process is controlled one.
• The working fluid after condensation process is both in the liquid and vapour state, and these do not form a homogeneous mixture. It is rather difficult to compress the two phase mixture isentropically. 
• The vapour has a large specific volume and to accomodate greater volumes, the size of the compressor becomes quite big.
• For running a large sized compressor more powder is required and that results in a poor plant efficiency.
• Carnot cycle has high specific steam consumption, large back work ratio and low work ratio.
• The steam at exhaust from the turbine is of low quality i.e., high moisture content. The liquid water droplets cause pitting and hence erosion of the turbine blades.

So, carnot cycle is not suitable for steam power plant.

Just for an idea,
This is how the classical Carnot Heat Engine Looks...

[Database Management System] Super Key, Primary key and Foreign key in Context of relational database model

SUPER KEY

• A set of one or more attribute taken collectively which can identify a record uniquely from a relation.
• Example:  {roll_no} is a super key in student relation.
• Let AK be a set of attributes of a relations R and let t1 and t2 be the two tuples in r of R, then AK will be the super key of relation R if t1{AK} is not equal to t2{AK}
•           A           B           C                                                                                                                                                         a1          b1         c1                                                                                                                                                       a2         b2         c2                                                                                                                                                       a3         b3         c3                                                                                                                                                                                                                                                                                                                                     Here {AB}, {BC}, {AC}, {ABC} are super keys of R.
• The set of all attributes of a relation is a default super key of relation
• The super key contains extraneous attributes

PRIMARY KEY

• It is a specific key which consist of most independent attributes.
• When an attribute is defined to be  a primary key, then every incoming value is tested to be non-null and unique.
• Example:                                                                                                                                                                    Roll_no is primary key to student relation

FOREIGN KEY

• In a relation, the column whose values corresponds to the values of key column in other relation is called Foreign key.
• Example:                                                                                                                                                                                                                                                                                                                                                           Product= Pro_code Name | Supp_code                 (Pro_code ->Product_Code,                                                                                                                               Supp_code -> Supplier_Code,                                                                                                                   So here Pro_code is primary key)

           Supplier=Supp_code | Supp_name                            (Supp_code -> Supplier_Code,                                                                                                                                     Supp_name -> Supplier name,

                                                                                                           So here Supp_code is Foreign Key)

(Note all these definitions or statements were taken from different sources from web ) 

:) 

[E-Commerce] Different Components Of A Business Model

                                  DIFFERENT COMPONENTS OF A BUSINESS MODEL

The Challenges differ from industry to industry, but let's discuss about some seven basic components of business model:

Reaching Customers:
It's a proverb "Built a better mousetrap, and the world will beat a path to your door." The reality is that even if you did, no one would find you. Even when you know who your prospects are, it's usually difficult and costly to reach them. You have to find them via the internet and email or the old fashioned way-through broadcast media,print ads, direct mail, telemarketing or references or by cold-calling. And these potential customers are not likely to be waiting to hear from you and may not respond to you. So be sure you know how you are going to find and reach them.

Differentiating Your Product:
You think you have got the very best solution, but so does the other girl (or guy). There's always competition, whether you realize it or not. Smart marketing executives know how to develop unique product-positioning strategies that highlight a product's true value. You need to thoroughly understand the competition and effectively communicate the unique advantages of your product.

Pricing:
One of the most basic decisions you have to make is how much you're going to change for your product or services. Giving your stuff away is the way to go on the web, but remember that you still need to figure out how you are eventually going to make money-you can't make it up on volume. Start by understanding how much customer's value what they're gaining from you. Then you need to estimate your total costs, analyze the competitive landscape, and map out your long-term strategy. For your company to survive, your product's price must be greater that its overall cost.

Selling:
Persuading customers to buy a product that they need is one of the most important skill an entrepreneur must learn. You're going to be selling at every juncture. So you have to understand what it takes to close a deal and put together the necessary sales process. And this process has to be perfectly conceived. Be sure you test your selling strategy.

Delivery/Distribution:
This is easy on the Internet. But for big-ticket items, you usually require a direct sales force, for mid-range products, distributors or value-added resellers and for low-priced items, retail outlets or the internet. It's different in every industry and for every type of product, but you have to get this right. Your products needs to be designed and packaged for the channel through which they will be distributed to customers.

Supporting Customers:
In addition to teaching customers how to use your product, you need to ensure that you can deal with defects and returns, answer product questions and listen to and incorporate valuable suggestions for improvement. You may need to provide consulting services to help customers integrate and implement your products. If your product is critical component of a business, you may also need to provide 24/7 onsite or web support.

Achieving Customer Satisfaction
The Ultimate success or failure of a business depends on how much it helps customers achieve their objectives. happy customers will become your best sales people and buy more from you. unhappy customers will become your biggest liability.



In Case if you don't know:

Function of a Business Model:-
1. To articulate the value proposition
2.To identify a market segment
3.To define the structure of the firm's value chain
4.To specify the revenue generation mechanism
5.To describe the position of the firm within the value network
6.To formulate the competitive Strategy



(Note: This definitions and statements were taken from different sources on web, they are of their respective owners) :)

[WINDOWS] Windows Keyboard Shortcuts [98,xp,7,8,10]

                                          WINDOWS KEYBOARD SHORTCUTS

WINDOWS 98 Shortcut Keys:

Press	To
ARROW KEY	Select the icon or taskbar button adjacent to starting point in the direction of the arrow while working on Desktop or Taskbar.
F1	Display Help information for the active object or the window as a whole.
ALT+letter key, where the key is the underlined	Select a menu, or select or clear the check box by the letter underlined in the menu name.
ALT+BACKSPACE or CTRL+Z	Undoes the last action (Undo command in Edit menu); use within a window. Note that not all actions, such as shutting down, can be undone.
ALT+ENTER	Switch view from current application window to next open application window, including minimized windows on the taskbar; press ESC more than once to switch through successive windows.
ALT+SHFT+ENTER	Switch view from current application window to next open application window, including minimized windows on the taskbar in the reverse direction; press ESC more than once to switch through successive windows.
ALT+ENTER	Display the properties of a selected item while working in a window.
ALT+ESC	Switch view from current application window to next open application window, including minimized windows on the taskbar; press ESC more than once to switch through successive windows.
ALT+SHFT+ESC	Switch view from current application window to next open application window, including minimized windows on the taskbar in the reverse direction; press ESC more than once to switch through successive windows.
ALT+F4	Close the active application window.
ALT+HYPHEN	Display Document menu from the leftmost icon on the main toolbar of the active document window.
ALT+M	Minimize all windows when taskbar has been selected.
ALT+PRINTSCREEN	Copy the active window to the Windows Clipboard.
ALT+SHFT+BACKSPACE	Redo the previously undone action; works within a window.
ALT+SPACEBAR	Open the menu of the leftmost icon on the main toolbar bar of the active window; this menu typically contains the following commands: Restore, Move, Size, Minimize, Maximize and Close.
ALT+SPACEBAR+C	Close the active window.
ALT+SPACEBAR+N	Minimize the active window.
ALT+SPACEBAR+R	Restore the active window.
ALT+SPACEBAR+X	Maximize the active window if it is minimized.
ALT+TAB	Move from active application window to the previously used application window; to select an application from a list of the open applications, hold ALT down and press TAB more than once to move through the list from left to right.
ALT+SHFT+TAB	Move from active application window to the previously used application window; to select an application from a list of the open applications, hold ALT and SHIFT down and press TAB more than once to move through the list from right to left.
Any printing character	Select the next icon with the specified name or initial letter while working on Desktop or Taskbar.
Any printing character	Select the menu command with the underlined character (access key) on an open menu within the window.
Any printing character	Select the next icon with the specified name or initial letter while working in Windows Explorer- Tree View; repeating the character selects successive items beginning with the same character.
Any printing character	Move to the next item with the specified name or initial letter when working in dialog boxes. Use BACKSPACE to change; in a multiple selection list box, this command moves to an item without selecting it.
CTRL+SHFT+ANY ARROW KEY	Highlight a selected block of text.
CTRL+SHFT+DRAG A FILE	Create a shortcut icon for a selected file in a selected place.
CTRL+SPACEBAR	Select the active item; use after moving with the CTRL key to select separate groups of items.
CTRL+SPACEBAR	Deselect the active item; use after moving with the CTRL key to select separate groups of items.
CTRL+UP ARROW	Move the insertion point to the beginning of the previous paragraph.
CTRL+V	Paste a copied item(s) from the Clipboard into a selected location (You also can choose Paste from the Edit menu.).
CTRL+X	Copy and remove the selected item(s) from their original location to the Clipboard. (You also can choose the Cut command from the Edit menu.).
CTRL+Z	Undo the last action; note: some actions, like Shutdown, cannot be undone (You also can choose Undo from the Edit menu.).
DELETE	Delete the selected item(s), or to delete the character to the right of the cursor; if items are files they will be moved to the Recycle Bin.
DOWN ARROW or UP ARROW	Disply the next or previous tab page in dialog boxes with tabs.
ENTER	Opens the selected menu when focus is on the menu title, but activates a menu item when focus is on a menu item. If the selected menu item is unavailable, ENTER closes the menu.
ESC	Close an open menu and return to the parent menu if there is one, or return to the menu title. If already at the menu title, return to position previous to activating the menu bar.
ESC	Cancel the current task.
F10 or ALT	Activate, or select, the main toolbar beginning with the first toolbar option on the left, usually File; after the first option is activated you can navigate through toolbar and menu options using the appropriate ARROW keys; press F10 or ALT again
F2	Rename a selected item (A bold rectangle appears around the title creating a text box, type the new name and press ENTER;Press ESC to cancel. Some icons on the desktop cannot be renamed).
F3	Open the Find All Files dialog box.
F4	Open the drop-down list box on the toolbar. Pressing F4 again moves the keyboard focus back to the previously used item.
F5	Refresh the current window (You also can choose Refresh from the View menu.).
F6 or TAB	Move between active panes and the toolbar.
END	Select the last item in the current list.
CTRL+HOME	Move to the first item in the current list without selecting it.
CTRL+END	Move to the last item in the current list without selecting it.
SHIFT+HOME	Select the first item in the list and additional items below it.
SHIFT+END	Select the last item in the current list and additional items above it.
HOME	Select the first item on the tree, when working in Windows Explorer - Tree View.
HOME	Select the highest setting in a dialog box with slide out menus.
END	Select the lowest setting in a dialog box with slide out menus.
HOME	Select the first item in a list box.
END	Select the last item in a list box.
SHIFT+HOME	Select the first item and additional items in an extended selection list box.
SHIFT+END	Select the last item and additional items in an extended selection list box.
CTRL+HOME	Move to the first item in an extended selection list box without selecting it. In a multiple selection list box, this moves cursor without changing the selection.
CTRL+END	Move to the last item in an extended selection list box without selecting it. In a multiple selection list box, this moves cursor without changing the selection.
LEFT ARROW	Close a branch, or select the parent of the current item, when working in Windows Explorer - Tree View.
LEFT ARROW or RIGHT ARROW	Switch the focus between menus on the menu bar in the direction of the arrow. If the original menu was open, the target menu is opened as well, and the first item in it gets the focus.
LEFT ARROW	Select the next lower setting in a dialog box with slide out menus.
UP ARROW	Select the next lower setting in a dialog box with slide out menus.
MINUS SIGN (on the numeric keypad)	Close everything under the current selection when working in Windows Explorer - Tree View.
PAGE DOWN	Select a lower or higher setting when working in a dialog box with slide out menus, depending on the application; this is the equivalent of pressing an arrow key many times.
PAGE UP	Select a lower or higher setting when working in a dialog box with slide out menus, depending on the application; this is the equivalent of pressing an arrow key many times.
PAGE UP	In Windows Explorer, go the top item on the screen. Use a second time to select the item one screen above.
PAGE DOWN	In Windows Explorer, go the bottom item on the screen. Use a second time to select the item one screen below.
SHFT+PAGE UP	In Windows Explorer, select additional items above an already selected item.
SHIFT+PAGE DOWN	In Windows Explorer, select additional items below an already selected item.
CTRL+PAGE UP	In Windows Explorer, move to additional items above an already selected item, without selecting the additional items.
CTRL+PAGE DOWN	In Windows Explorer, move to additional items below an already selected item, without selecting the additional items.
PAGE UP	In Windows Explorer Tree View, move to the top item on the screen. Use a second time to move up one screen.
PAGE DOWN	In Windows Explorer Tree View, move to the bottom item on the screen. Use a second time to move down one screen.
PAGE UP	In dialog boxes and combo boxes, move a selected item up one screen.
PAGE DOWN	In dialog boxes and combo boxes, move a selected item down one screen.
SHIFT+PAGE UP	In an extended selection list box, select additional items above an already selected item.
SHIFT+PAGE DOWN	In an extended selection list box, select additional items below an already selected item.
CTRL+PAGE UP	In an extended selection list box, move to additional items above an already select item, without selecting the additional items. In a multiple selection list box, use to move without changing the selection.
CTRL+PAGE DOWN	In an extended selection list box, move to additional items below an already select item, without selecting the additional items. In a multiple selection list box, use to move without changing the selection.
PLUS SIGN (on the numeric keypad)	In Windows Explorer, Tree view, expand everything under the current selection back to a previously opened state, or use to open only one level if it has not previously been opened.
PRINT SCREEN	Copy an image of the screen to the Windows Clipboard.
RIGHT ARROW	In Windows Explorer, Tree view, open a branch, or select the first item in the branch.
RIGHT ARROW	in dialog boxes with the slide out option, select the next highest setting.
DOWN ARROW	in dialog boxes with the slide out option, select the next highest setting.
RIGHT ARROW or LEFT ARROW	Use with tabbed dialog boxes and when the focus is on a tab selector, to choose the next or previous tab in the current row and to display the page.
SHFT	Bypass the AutoPlay feature by holding the SHIFT key down while you insert a CD-ROM ; hold down the SHIFT key while Microsoft Word is loading to suppress the AutoExec macro.
SHFT+ANY ARROW KEY	Select more than one item in a window or on the desktop in the direction of the chosen ARROW KEY, or to select text within a document.
SHIFT+DELETE	Delete selected item(s) immediately without moving the item(s) to the Recycle Bin.
SHIFT+F10 or Application key (also the right mouse	Display a shortcut menu that shows a list of commands relevant to the selected object.
SHIFT+F8	In extended selection list box, move without changing the selection. You can then press CTRL+SPACEBAR or SHFT+SPACEBAR to select additional items. The list box returns to normal operation when you press SHFT+F8 a second time or switch to another
SHIFT+INSERT OR CTRL+V	Paste copied items(s) from the Clipboard (You also can choose the Paste command from the Edit menu.).
SHFT+SPACE	Extend the selection to the current item; if you have already selected more than one item, it selects only the items from the first item you selected to the current item.
SHIFT+SPACE	Extend the selection from the last selected item to the current item in an extended selection dialog box, combo box or list-box.
SPACE	When typed alone, selects the current item if it is not already selected. Use after moving with the CTRL key to select separate groups of items.
SPACEBAR or CTRL+SPACE	Select or deselect the current item in an extended-selection list box.
TAB	Move between the last selected icon on the desktop, the Start button on the taskbar, and the taskbar as a whole. There is no visual indication of the focus on the taskbar, but you can use the arrow keys to move between the taskbar buttons. You also
DOWN ARROW	Open a selected menu; DOWN ARROW selects the next command in the list.
UP ARROW	Open a selected menu; UP ARROW selects the previous command in the list.
UP ARROW	Select the next visible object above when working in Windows Explorer-Tree View.
DOWN ARROW	Select the next visible object below when working in Windows Explorer-Tree View.
UP ARROW	Select the previous item in a dialog box.
DOWN ARROW	Select the next item in a dialog box.
SHFT+UP ARROW	In an extended selection list box, select additional items above an already selected item.
SHFT+DOWN ARROW	In an extended selection list box, select additional items below an already selected item.
CTRL+UP ARROW	Move to additional items above a selected item without selecting the additional items.
CTRL+DOWN ARROW	Move to additional items below a selected item without selecting the additional items.
WIN+F1	Display Windows Help.
Windows logo key or CTRL+ESC	Opens the Start menu from the taskbar. When you use CTRL+ESC, you can press ESC again to place the keyboard focus on the Start button. When you use the Windows logo key, pressing ESC again closes the Start menu.
Windows logo key+BREAK	Open the System Properties dialog box. (You also can choose the Systems item in Control Panel.).
Windows logo key+CTRL+F	Open the Find Computer dialog box. (You also can choose the Computer command from the Find item in the Start menu.).
Windows logo key+E	Open the Windows Explorer. (You also can choose the Windows Explorer command from the Program item in the Start menu.).
Windows logo key+F	Open the Find All Files dialog box. (You also can choose the Files Or Folders command from the Find item in the Start menu.).
Windows logo key+M	Minimize all open windows. The keyboard focus goes to the least recently selected icon on the desktop.
Windows logo key+M+SHFT	Expand previously opened windows and return focus to the most recently used application.
Windows logo key+number	This shortcut key is reserved for use by computer manufacturers.
Windows logo key+R	Display the Run dialog box. (You also can choose the Run command in the Start menu.).
Windows logo key+TAB	Select and cycle through the taskbar buttons.
ARROW KEY	Select the next item in the indicated direction while working in Windows explorer; add SHIFT to select or deselect additional items; add CTRL to move to the item without selecting it; in Details View there is only one column, so RIGHT and LEFT ARRO
ASTERISK (on the numeric keypad)	Expand view of everything under the current selection when working in Windows Explorer-Tree view.
BACKSPACE	Display the contents of the parent directory of an active directory while working in Windows Explorer; it may open a new window, depending on the options selected.
BACKSPACE	Display the contents of the parent directory of an active directory while working in Windows Explorer-Tree View; it may open a new window, depending on the options selected.
BACKSPACE	View the folder one level up in My Computer or Windows Explorer-TreeView.
CTRL+A	Select all the items in the active window (You also can choose Select All from the Edit menu.).
CTRL+ALT+DELETE	Display the Close Program dialog box in order to close active programs, or to shut down the entire computer system.
CTRL+ALT+DELETE	Open the Windows NT Security dialog box to choose from the following options: Lock Workstation, Logoff, Shut Down, Change Password, Task Manager, and Cancel; if you are not logged on, command opens the logon dial
CTRL+BACKSPACE	Undo previous action taken within a window.
CTRL+C	Copy selected item(s) to the Windows Clipboard when working in Windows Explorer.
CTRL+DOWN ARROW	Move the cursor to the beginning of the next paragraph within a window.
CTRL+DRAG A FILE	Copy a selected file to a folder by dragging the file to the folder.
CTRL+ESC	Display Windows Start menu.
CTRL+ESC and then R	Display Run dialog box after displaying Start menu.
CTRL+F or F3	Display the Find All Files dialog box while working in Windows Explorer.
CTRL+F4	Close the active document window.
CTRL+F6	Go to the next document window in the active application. Add SHIFT to go to the previous document window.
CTRL+SHFT+F6	Go to the previous document window in the active application.
CTRL+G	Display the Go To Folder dialog box (You also can choose Go To from the Tools menu).
CTRL+INSERT OR CTRL+C	Copy the selected item(s) to the Clipboard. (You also can choose the Copy command from the Edit menu.).
CTRL+LEFT ARROW	Move the cursor's position to the beginning of the previous word.
CTRL+N	Open the New dialog box.
CTRL+O	Display the Open dialog box (You also can choose the Open command from the File menu.).
CTRL+P	Display the Print dialog box (You also can choose the Print command from the File menu).
CTRL+PAGE DOWN or CTRL+TAB	Display next tab when working with a dialog box with multiple tabs.
CTRL+PAGE UP or CTRL+SHFT+TAB	Display the previous tab when working with a dialog box with multiple tabs.
CTRL+RIGHT ARROW	Move the cursor's position to the beginning of the next word.
CTRL+S	Open the Save dialog box (You also can choose the Save command from the File menu).
Windows XP Keyboard Shortcuts: ALT+- (ALT+hyphen)       Displays the Multiple Document Interface (MDI) child window's System menu ALT+ENTER                           View properties for the selected item ALT+ESC                                   Cycle through items in the order they were opened ALT+F4                                      Close the active item, or quit the active program ALT+SPACEBAR                   Display the System menu for the active window ALT+TAB                                   Switch between open items ALT+Underlined letter      Display the corresponding menu BACKSPACE                            View the folder one level up in My Computer or Windows Explorer CTRL+A                                      Select all CTRL+B                                      Bold CTRL+C                                       Copy CTRL+I                                        Italics CTRL+O                                      Open an item CTRL+U                                      Underline CTRL+V                                      Paste CTRL+X                                      Cut CTRL+Z                                       Undo CTRL+F4                                    Close the active document CTRL while dragging           Copy selected item CTRL+SHIFT while dragging           Create shortcut to selected item CTRL+RIGHT ARROW                        Move the insertion point to the beginning of the next word CTRL+LEFT ARROW                            Move the insertion point to the beginning of the previous word CTRL+DOWN ARROW                        Move the insertion point to the beginning of the next paragraph CTRL+UP ARROW                                  Move the insertion point to the beginning of the previous paragraph SHIFT+DELETE                                        Delete selected item permanently without placing the item in the Recycle Bin ESC                                           Cancel the current task F1                                               Displays Help F2                                               Rename selected item F3                                               Search for a file or folder F4                                               Display the Address bar list in My Computer or Windows Explorer F5                                               Refresh the active window F6                                               Cycle through screen elements in a window or on the desktop F10                                             Activate the menu bar in the active program SHIFT+F10                           Display the shortcut menu for the selected item CTRL+ESC                             Display the Start menu SHIFT+CTRL+ESC            Launches Task Manager SHIFT                                       when you insert a CD Prevent the CD from automatically playing WIN                                           Display or hide the Start menu WIN+BREAK                        Display the System Properties dialog box WIN+D                                      Minimizes all Windows and shows the Desktop WIN+E                                       Open Windows Explorer WIN+F                                       Search for a file or folder WIN+F+CTRL                        Search for computers WIN+L                                        Locks the desktop WIN+M                                       Minimize or restore all windows WIN+R                                        Open the Run dialog box WIN+TAB                                  Switch between open items WINDOWS-7 Shortcut Keys: 1. Managing 'Windows' in Windows 7 Move and Resize Active Window Win+Arrow Down Set window to Restored (if Maximized) or Minimized (if Restored) Win+Arrow Up Maximize window (if Restored) Win+Shift+Arrow Down/Win+Shift+Arrow Up Maximize Restored window vertically / Restore window to previous state Win+Arrow Right/Win+Arrow Left Move Restored window to left/center/right. Works across multiple monitors Win+Shift+Arrow Right/Win+Shift+Arrow Left Move window to left monitor / to right monitor when using multiple monitors Alt+Space Opens the title bar menu Alt+Space+Enter Restore Window Alt+Space+X Maximize Window Alt+Space+N Minimize Window F11 Turn full page view on or off 'Maximized' means full screen, 'Restored' means variable window size, and 'Minimized' means minimized to taskbar. Switch between Applications Alt+Tab, Alt+Shift+Tab Cycles through open programs in taskbar. Hold alt and continuously press tab to move forward between applications. Release keys to switch to application selected. Add shift to reverse direction. Alt+Ctrl+Tab, then use arrow keys to select application Cycles through open programs in taskbar without needing to hold alt continuously. Pressalt+ctrl+tab once, then continue with arrow keys and press enter on application. Alt+Esc/Alt+Shift+Esc Cycle through programs on taskbar in the order they were opened or accessed Win+Tab Cycle through programs using Aero Flip 3D Ctrl+Win+Tab Cycle through programs on Taskbar using Aero Flip 3D Win+G Cycle through Gadget Window Manage Multiple Windows Win+D Minimize all windows on all Monitors. Press again to restore previous state Win+M Minimize all windows on current Monitor Win+Shift+M Restore previously minimized windows on current Monitor Win+Home Set all windows to Minimized on current Monitor except active Win+Space Preview Desktop / make windows transparent (May not work with all Settings) . Accessing Windows Features Win+E Start Windows Explorer (in My Computer) Win+R Open the Run window Win+F Open Windows Search. f3 on empty desktop works, too. Win+L Lock the keyboard/ computer Win+F1 Display Windows Help Alt+Shift Change keyboard language layout if multiple language layouts are active* Shift when inserting CD or DVD Prevent CD or DVD from automatically playing Win+P Choose Presentation Display Mode Win+X Open Mobility Center * When working with multiple Keyboards Layouts (e.g. Spanish/English/German). Add unlimited Layouts under Regional settings and activate language bar in Taskbar to see current language. Switch with shortcut any time. 3. Windows 7 Taskbar Win or Ctrl+Esc Activate Start Button. Then use arrow keys, space and enter to navigate within Start Menu Win+T Go to first item in taskbar, continue with arrow keys Win+B Go to first item in system tray Shift+click on a taskbar item Start new instance of taskbar item Ctrl+Shift+click on a taskbar item Start new instance of taskbar item as administrator Shift+right-click on a taskbar item Show the window menu for the program Win+1...9 Switch to application in position N on taskbar (or launch pinned application) Shift+Win+1...9 Start new instance of taskbar item in position N on taskbar Unfortunately, Microsoft removed the possibility to select multiple taskbar items in Windows 7 4. Navigating Desktop Arrow Keys Navigate between and select single icons on desktop (when focus is on the desktop) Home/End Select first / select last object on desktop Enter Launch active icon Shift+F10 Activate context menu of active icon by simulates right mouse button. Once in the context menu usearrow keys, a-z and enter to select item tab, shift+tab on empty desktop Navigate between desktop, the quick-launch bar, task bar and notification bar. Then use arrow keysand enter or space to activate specific icons A, B, C, ... Pressing the initial letter of the name of any objects will highlight the respective application or folder. Continue typing the object name if multiple objects start with the same letter 5. Windows Explorer Basics Win+E Start Windows Explorer (My Computer) Alt+Arrow Up Go up one folder Alt+Arrow Left/Alt+Arrow Right Go to previous folder / go to next folder Tab/Shift+Tab Switch focus forward/ backward between Address bar, Search Bar, Toolbar, Navigation Pane, and File List (Default is usually File List) Alt+D or f4 Jump to the Address bar and select absolute address. Copy address with ctrl+c if desired Ctrl+E or ctrl+f Jump to Search Box in Explorer Ctrl+N Open new instance of Windows Explorer F11 Maximize window Navigate File List and Navigation Pane Arrow Keys Navigate between files and folders Enter Open folder or start application Home/End Jump to first / jump to last item F2 Change the file name of active item F2, then arrow left/Arrow Right Move one character to the left / to the right in item name F2, then ctrl+Arrow Left/Ctrl+Arrow Right Jump one word to the left / to the right of item name F2, then home /End Jump to beginning / jump to end of item name F2, then ctrl+a Select complete object name including suffix (default excludes suffix) Arrow Left/Arrow Right Expand folder / collapse folder (navigation pane only) File List Alt+P Display or hide Preview Pane Alt+V then D View details. Check View menu for more options Alt+V then X View extra-large icons. Check View menu for more options Ctrl+mouse scroll wheel Change size of icons Select Items in File List and Navigation Pane Shift+Arrow Up/Arrow Down Select multiple adjacent items (directly above or below) ctrl with arrow keys and space Select multiple non-adjacent items. Hold ctrl, use arrow keys to move to next item, and pressspace to add/remove from selection Ctrl+A Select all A ...Z and 1..9 Press the initial letter any item to jump to it. Continue typing the full name if multiple items start with the same letter Manipulate Items in Explorer Ctrl+C, Ctrl+X, Ctrl+V ctrl+C for copy, Ctrl+X for cut and Ctrl+V for paste Ctrl+Z Undo an action Ctrl+Y Redo an action Delete Delete an item and place it into the Recycle Bin Shift+Delete Delete an item permanently without placing it into the Recycle Bin Shift+F10 Activate context menu of active object. Replaces the right mouse button. Once in the context menu use arrow keys, a-z and enter to get to the selection Ctrl+Shift+N Create new folder Alt+Enter Open Properties dialog box 6. Photo Viewer Arrow Left/Arrow Right Go to next / go to previous photo Ctrl+. Rotate photo clockwise Ctrl+, Rotate photo counter-clockwise [+]/- Zoom in / zoom out (or mouse wheel) Ctrl+0 (zero) Fit to Window Delete Delete current photo Shift+Delete Permanently delete current photo Alt+Enter Show properties of current photo Alt+E or Ctrl+S Email current photo Ctrl+C Copy current photo file to clipboard Alt+O Open current photo in other application (e.g. Paint of Office) 7. Dialog Boxes Ctrl+Tab/Ctrl+Shift+Tab Move forward / move backwards through tabs Tab/Shift+Tab Move forward / move backwards through options Alt+underlined letter Perform the command (or select the option) that goes with that letter Enter Replaces clicking the mouse for many selected commands Space Select or clear the check box if the active option is a check box Arrow Keys Select a button if the active option is a group of option buttons F4 Display the items in the active list Backspace Open a folder one level up if a folder is selected in the Save As or Open dialog box 8. Windows Admin Admin Tasks Ctrl+Win+F Search for Computers (with Active Directory activated) Win+Pause/Break Display System Properties which holds system properties, computer name, device manager and so on Ctrl+Shift+Esc Opens Windows Task Manager Remote Desktop Alt+Page Up/Alt+Page Down Move between programs from left to right / from right to left Alt+Insert Cycle through programs in the order that they were started in Alt+Home Display the Start menu Ctrl+Alt+pause/break Switch between a window and full screen Ctrl+Alt+End Display the Windows Security dialog box Alt+Delete Display the system menu 9. Windows Help Tab Move between links Alt+C Display the Table of Contents Alt+N Display the Connection Settings menu F10 Display the Options menu Alt+Arrow Left/Alt+Arrow Right Move back / move forward to the previously/ next viewed topic Alt+A Display the customer support page Alt+Home Display the Help and Support home page Home/End Move to the beginning / to the end of a topic Ctrl+F Search the current topic. Press tab to leave Ctrl+P Print a topic F3 Move the cursor to the search box. Press tab to leave 10. Ease of Access and Magnifier Ease of Access Win+U Open Ease of Access Center Press Shift five times. Turn Sticky Keys on or off Press Num Lock for five seconds Turn Toggle Keys on or off Right Shift for eight seconds Turn Filter Keys on or off left Alt + left Shift +Num Lock Turn Mouse Keys on or off left Alt + left Shift + prtScn Turn High Contrast on or off (Careful, will change theme!) Magnifier Win+[+] Start Magnifier and zoom in Win+- Zoom out with Magnifier active Ctrl+Alt+I Invert colors in Magnifier display Win+Esc Exit Magnifier Ctrl+Alt+Arrow Keys Move the Magnifier windows WINDOWS 8 Shortcut Keys: 1. Getting around Windows 8 Start Screen and Desktop Win Toggle between Desktop and Start Screen (or open Apps) Ctrl+Tab On Start Screen: Switch Between Start Window and All Apps Window Win, then Ctrl+Tab Open All Apps Window Win, then start typing App Name Search and execute Apps Escape Close Start Screen and go to Desktop Win+E Run Explorer on Desktop Win+R Execute Run on Desktop Win+X Open Power User Commands on Desktop Alt+F4 Shutdown Windows Win+L Lock Computer Win+F1 Open Windows Help 2. Windows 8 Charme Shortcuts Tip: Pressing Escape typically closes most Charme menus. Win+C Open Windows Charme. Use arrow keys and enter to select item. Press Win+Q Search Charme / last search option Win+F Search Files Win+W Search Windows Settings Win+I Open Settings including Desktop, Control Panel, Personalization, PC Info, Help Win+H Share Charme Win+K Device Charme Win+S Search Settings Win+F Search Files Win+Z Show Options / App Bar in current Metro Apps if available. 3. Switch between Apps and Windows Alt+Tab and Alt+Shift+Tab Cycle between all Windows and Apps. Press and hold Alt key before pressing Tab. Release Tabon Window/App you want to open. While tabbing, add Shift to key combination to go backwards. Ctrl+Alt+Tab then Arrow Keys Cycle between open Apps without having to keep Alt pressed. Press keys once, then use Arrowkeys and Enter to select Window/App. Win+Tab and Win+Shift+Tab Same as Alt+Tab, but only includes Apps only, not Windows on Desktop Ctrl+Win+Tab, then Arrow keys Same as Ctrl+Alt+Tab, but only includes Apps, not Desktop Windows 4. Power User Commands Shortcuts These are also listed in the Power User Command Window. Sorted by their (subjective) importance. Win+X, P Control Panel Win+X, T Task Manager Win+X, E File Explorer (alternative: Win+e) Win+X, R Run (alternative: Win+r) Win+X, D Desktop (alternative: Win+d) Win+X, F Programs and Features Win+X, C Command Prompt Win+X, A Elevated Command Prompt (Admin) Win+X, Y System Information Win+X, M Device Manager Win+X, G Computer Management Win+X, B Mobility Center Win+X, O Power Options Win+X, V Event Viewer Win+X, K Disk Management Win+X, S Search 5. Managing Windows 8 Desktop Windows Win Go to desktop / switch between Desktop and Start Screen or Apps Win+Arrow Up Maximize Window across screen Win+Arrow Down Minimize Window (if Restored) or set Window to Restored (if Maximized) Win+Shift+Arrow Up Maximixe Window vertically Win+Arrow Right/Arrow Left Move Window to left/center/right. Works across multiple monitors Win+Shift+Arrow Right/ Arrow Left" Move window to left monitor / to right monitor when using multiple monitors Alt+Space Opens the title bar menu F11 Turn full page view on or off Alt+Q Close Window 6. Windows 8 Taskbar Win+T Go to first item in Taskbar, continue with arrow keys Win+B Go to first item in System Tray Shift+click on a taskbar item Start new instance of Taskbar item Ctrl+Shift+click on a taskbar item Start new instance of Taskbar item as administrator Shift+right-click on a taskbar item Show the window menu for the program Win+1...9 Switch to application in position N on Taskbar (or launch pinned application) Shift+Win+1...9 Start new instance of taskbar item in position N on Taskbar Unfortunately, Microsoft removed the possibility to select multiple taskbar items in Windows 7 (and did still not re-introduce in Windows 8) 7. Navigating Desktop Arrow Keys Navigate between and select single icons on desktop (when focus is on the desktop) Home/End Select first / select last object on desktop Enter Launch active object Shift+F10 Activate context menu of active icon by simulates right mouse button. Once in the context menu usearrow keys, a-z and enter to select item Tab, Shift+Tab on empty desktop Navigate between desktop, the quick-launch bar, task bar and notification bar. Then use arrow keysand enter or space to activate specific icons A, B, C, ... Pressing the initial letter of the name of any objects will highlight the respective application or folder. Continue typing the object name if multiple objects start with the same letter 8. Windows Explorer Basics Win+E Start Windows Explorer Alt+Arrow Up Go up one folder Alt+Arrow Left/ Alt+Arrow Right Go to previous folder / go to next folder Tab/Shift+Tab Switch focus forward/ backward between Address bar, Search Bar, Toolbar, Navigation Pane, and File List (Default is usually File List) Alt+D or F4 Jump to the Address bar and select absolute address. Copy address with ctrl+c if desired Ctrl+E or Ctrl+F Jump to Search Box in Explorer Ctrl+N Open new instance of Windows Explorer F11 Toggle full-screen mode Navigate File List and Navigation Pane Arrow Keys Navigate between files and folders Enter Open folder or start application Home/End Jump to first / jump to last item F2 Change the file name of active item F2, then Arrow Left/ Arrow Right Move one character to the left / to the right in item name F2, then Ctrl+ Arrow Left/Arrow Right Jump one word to the left / to the right of item name F2, then Home /End Jump to beginning / jump to end of item name F2, then Ctrl+A Select all/ complete object name including suffix (default excludes suffix) Arrow Left/Arrow Right Expand folder / collapse folder (navigation pane only) File List Views Alt+P Display or hide Preview Pane Alt+V then D View details. Check View menu for more options Alt+V then X View extra-large icons. Check View menu for more options Ctrl+mouse scroll wheel Change size of icons Select Items in File List and Navigation Pane Shift+Arrow Up/ Arrow Down Select multiple adjacent items (directly above or below) Ctrl with Arrow keys and Space Select multiple non-adjacent items. Hold ctrl, use arrow keys to move to next item, and pressspace to add/remove from selection Ctrl+A Select all A ...Z and 1..9 Press the initial letter any item to jump to it. Continue typing the full name if multiple items start with the same letter Manage Items in Explorer Ctrl+C, ctrl+X, ctrl+V Copy, Cut, Paste Ctrl+Z Undo an action Ctrl+Y Redo an action Delete Delete an item and place it into the Recycle Bin Shift+Delete Delete an item permanently without placing it into the Recycle Bin Shift+F10 Activate context menu of active object. Replaces the right mouse button. Once in the context menu use arrow keys, a-z and enter to get to the selection Ctrl+Shift+N Create new folder Alt+Enter Open Properties dialog box 9. The Rest Win+U Open Ease of Access Center Win+P Projector or second screen settings. Alt+Shift Change keyboard language layout if multiple language layouts are active*

WINDOWS 10 Shortcut Keys:

Windows key + A: Open the Action Center
Windows key + C: Launch Cortana in listening mode (for voice commands)
Windows key + I: Open the Settings app
Windows key + S: Launch Cortana
Windows key + Tab: Open Task View
Windows key + Ctrl + D: Create a new virtual desktop
Windows key + Ctrl + F4: Close the current desktop
Windows key + Ctrl + left or right arrow: switch between virtual desktops

Windows key (Windows 7 and up): Open/close the Start menu
Windows key + X (Windows 8.1 and 10): Open/close the Start button’s right-click context menu Windows key + left or right arrow (Windows 7 and up): snap current window to right or left of screenWindows key + E (Windows 7 and up): Launch File Explorer Windows key + L (Windows 7 and up): Lock the desktop
Alt + PrtScn (Windows 7 and up): Take a screenshot of current window and copy it to your clipboard Windows key + PrtScn (Windows 8.1 and 10): Take a screenshot of entire display and save to Computer > Pictures > Screenshots

Browser shortcuts (works in Edge and most other browsers)

Ctrl + T: Open new tab
Ctrl + D: Bookmark page
Ctrl + L: Highlight current URL (good for typing a new address or copying the current one)
Ctrl + Tab: Cycle through your open tabs
Ctrl + Enter: add “.com” to the end of a web address (e.g. type ‘google’ then Ctrl + Enter to get google.com)

(NOTE: This Information about shortcut keys of windows is collected from different sources from web)