Question Discussion & Solution

Six people: M, N, O, P, Q, and R.

1) Only two people sit between Q and N, who sit extreme left end of the row.

2) Q sits second to the left of R.

3) O is an immediate neighbor of R.

4) P and M are immediate neighbor to each other.

5) N is not immediate neighbor of M.

CONCEPT:

• Power is the ability to bend light and it is equal to the reciprocal of the focal length of the lens/mirror in meters.

Power (P) = 1/f

Where f is the focal length of the lens/mirror.

EXPLANATION:

As explained above, Dioptre is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres.

And since the S.I unit of the focal length is the meter (m).

So the S.I unit of power = 1/(SI unit of focal length) = m-1 = Dioptre (D).

1 m-1 = 1 D

CONCEPT:

Logic Gates:

• The logic gates are used in electronic circuits that give a certain output for a given set of Inputs.
• and which is based on a certain logic. 
• Input and output are in binary form that is 1 and 0.
• It is based on certain Logic.
• Some basic logic gates are AND gate, OR gate, NOT gate. 
• To build digital logic we develop a combination of these gates. 

AND Gate

•  If both the inputs are high, it produces a high output.
• The Boolean algebra for AND gate is X = A. B
• It means that if any of the input of A and B is zero, the output will be zero.
• If both are one, the output will be one.

The correct option is AND Gate. 

Additional Information

NOT gate:  

• It inverts the input. Whatever the input is given, it changes its value at the output.
• The Boolean algebra for NOT gate is X = X̅

The correct answer is World Wide Web.

Key Points

• Web service is a standardized medium to propagate communication between the client and server applications on the WWW (World Wide Web). 
  • A web service is a software system that supports interoperable machine-to-machine interaction over a network.
  • It has an interface described in a machine-processable format (specifically, Web Service Definition Language, or WSDL).
  • Web services fulfil a specific task or a set of tasks.
  • The nature of the interface hides the implementation details of the service so that it can be used independently of the hardware or software platform on which it is implemented and independently of the programming language in which it is written.

Additional Information

• A protocol is a set of rules or procedures for transmitting data between electronic devices, such as computers.
• The protocol that is used for transferring both text and binary files over the Internet is File Transfer Protocol (FTP).
• Hypertext Transfer Protocol (HTTP) is a protocol for transmitting hypermedia documents, such as HTML.
• Hypertext Transfer Protocol Secure (HTTPS) is a secure version of the HTTP protocol that uses encryption and authentication.

The correct answer is Alt+F4.

Key Points

• Alt+F4 is a shortcut key that is used to close the currently active window.
• To stop the current window this shortcut has been used.
• For example: if we pressed the shortcut key now while reading this page on your computer browser, it would close the browser window and all open tabs.

How to Use this Shortcut Key

• To use the keyboard shortcut Alt+F4, press Alt andF4 Key simultaneously.

• While running any program in Microsoft Windows, if Alt+F4 is pressed, it closes the currently active program.
• If no programs are open or we are at the desktop, pressing Alt+F4 opens the Shutdown window.

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Additional Information

Functions of other shortcut Keys in computer

• Alt + Tab
  • Alt+Tab  can be used to switch to any running program that has an application-level window.
  •  It can be used to alternate between the two most recent tasks.
  •  It acts as an alternate between a full-size window and the desktop.
• Alt+E
  • ​It is a shortcut key most often used to open the Edit file menu option for programs supporting a file menu.
  • In Google Sheets, pressing Alt+E opens the Edit file menu option.
  • In Chrome, pressing Alt+E opens the Chrome menu.
  • In Microsoft Internet Explorer and Mozilla Firefox, pressing Alt+E opens the Edit file menu.
• F1
  • Used as the help key in almost every program, it opens a help screen when this key is pressed.
  • Windows Key + F1 opens the Microsoft Windows help and support center.
  • It opens the Task Pane.
• Cntrl+1
  • Ctrl+1 is a shortcut key most often used to switch to the first tab in a browser or other programs with tab support.
  • The "1" (one) used with this shortcut is the "1" at the top of the keyboard, not on the numeric keypad.
  • It is also known as  Control 1 and C-1.