Question Discussion & Solution

The correct answer is Boy pushing wall in a room.

Key Points

• Boy pushing the wall in the room is not an example of work done.
  • When a boy pushes a wall, he is applying force on the wall. We see that the wall shows no displacement.
  • Work is given as the product of the forces and the displacement in the same direction.
  • Hence the work done is zero.

Additional Information

• Work is done when a force moves. Everyday examples of work include walking up a flight of stairs, lifting heavy objects, pulling a sled and pushing a shopping trolley, Applying pressure on a pebble lying on the surface, raising a book to a height.
  • Work is not done when holding a bag stationary or a book at arm's length because although a force is being applied, the force does not move.

The correct answer is Mangifera indica.

Key Points

• Mangifera indica is the botanical name of mango.
  • In this name, Mangifera represents the genus while indica is a particular species.
• Scientific name
  • This system was given by Carolus Linnaeus.
  • Each name has two components – the Generic name and the specific epithet.
  • This system of providing a name with two components is called Binomial nomenclature.

Additional Information

• Monoon longifolium is an Asian small tree species in the family Annonaceae. Common names include false Ashoka, the Buddha tree, the Indian mast tree, and the Indian fir tree.
• Cocos nucifera is a Coconut tree. It is a tall tree that is native to tropical islands in the western Pacific. 
• Casuarina is a nitrogen-fixing tree through symbiotic relationship with an actinomycete called Frankia. Common names include coast sheoak, beach casuarina, beach oak, beach sheoak, beach pine, whistling tree, etc.

1. Some students can either be mischievous or Intelligent.

2. Some Intelligent person can either be mischievous or students.

Thus there are some relation between all the three i.e students, intelligent and mischievous

Now, according to this, the most suitable Venn diagram is-

Hence, Option (4) is correct.

Additional InformationMischievous: A person likes to have fun by playing harmless tricks on people or doing things they are not supposed to do.

A keyboard is for putting information including letters, words, and numbers into the computer. A keyboard's primary function is to act as an input device. Using a keyboard, a person can type a document, use keystroke shortcuts, access menus, play games and perform a variety of other tasks.

Key Points

• A modifier key is a key on a computer's keyboard that's only used in conjunction with another key.
• Modifier keys are often used with other keys to perform computer keyboard shortcuts and other commands.
• For example, in many text editor programs pressing the Ctrl+A selects all text.

Additional Information

• The function keys or F keys are lined across the top of the keyboard and labeled F1 through F12. These keys act as shortcuts, performing certain functions, like saving files, printing data, or refreshing a page.
  • For example, the F1 key is often used as the default help key in many programs. The F5 key is used in an Internet browser to refresh or reload a web page. The function of these keys can differ by the operating system and by a software program.
• A special key or media key, or multimedia key is a keyboard key that performs a special function not included with the traditional 104-key keyboard.
  • For example, the picture shows a Logitech keyboard.
• An ergonomic keyboard is a keyboard designed for comfort, ease of use, and reduced strain on the user.
  • Such keyboards may include features like concave or tapered keys, keys that are well-spaced, or keys that separate and angle out from a central pivot point.

Therefore, based on the above information The keys of a keyboard, which are used to modify the input of other keys, are called modifier keys.

• Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory (RAM), independent of the central processing unit (CPU)
• Disk drive is a hardware subsystem