Question Discussion & Solution

The correct answer is Video Graphics Array.

• VGA is Video Graphics Array which is a computer chipset standard for displaying colour graphics. 
• VGA is a popular display standard developed by IBM and introduced in 1987.
• It provides 640 x 480 resolution color display screens with a refresh rate of 60 Hz and 16 colors displayed at a time. 
• VGA utilizes analog signals, which means it's only capable of lower resolutions and a lower quality display on screens.

• The VGA connector is used for display devices and is used to connect a computer to a monitor, projector, or TV.

The correct answer is Scanner.

Key Points

• Scanner:
  • Scanner is an input device and can be used to scan images as well as text documents.
  • Scanner is not a pointing input device.
• ​Pointing device
  • A pointing device is an input interface that allows a user to input spatial data to a computer. 
  • Common pointing devices
    • Mouse
    • Trackball
    • Joystick
    • Pointing stick
    • Wii Remote
    • Finger tracking
    • Graphics tablet
    • Stylus
    • Finger tracking

Additional Information

• Track Ball:
  • The trackball is a pointing device consisting of a ball housed in a socket containing sensors to detect rotation of the ball about two axes, similar to an upside-down mouse..
  • Tracker balls are commonly used on CAD workstations​
• Digitizing Tablet:
  • A digitizer tablet is a peripheral device that allows users to draw on a computer screen.
• Joystick:
  • A joystick is a lever-type device that can be moved in several directions.
  • Used to control the movement of an image on a computer or similar display screen.

CONCEPT:

Rutherford’s Model of the Atom:

• He bombarded the beam of alpha particles on a very thin gold foil.
• While bombarding he observes the number of scattering of particles –
  • Most of the particles passed either un-deviated or with a very small deviation.
  • Some deviated by large angles
  • 1 out of 8000 was deflected by more than 90°
• The conclusion to this deflection:
  • Most of the space of an atom is empty.
  • At the centre of an atom having a tiny positively charged particle called a nucleus.
  • The centre nucleus has all the mass of an atom.
  • The amount of positive charge at the nucleus is equal to the total amount of negative charges on all the electrons of the atom.
  • All the electrons revolve around the nucleus and coulomb force provide the centripetal force

​

EXPLANATION:

• After the α -particles scattering experiment, the following conclusions were made by Rutherford as regard as atomic structure:

• Most of the mass (at least 99.95%) and all of the charge of an atom concentrated in a very small region is called the atomic nucleus. Therefore option 4 is correct.
• The nucleus consists of proton and neutron, in which proton was first discovered by Rutherford but neutrons were later discovered by James Chadwick in 1932.
• In an atom, there is maximum empty space and the electrons revolve around the nucleus in the same way as the planets revolve around the sun and the nnumber of protons and electrons inside an atom are equal under normal conditions (non-ionized). 

Key Points 

Spleen is an organ on the left side of the abdomen below the stomach. 

It performs two major functions:

1. Storage of blood - Blood vessels of spleen can alter their thicker and become wider or narrower depending on the situation. In case of emergency situations like trauma & severe injuries where a lot of blood gets lost, the spleen expand its vessels and hold the blood. This reserve blood is then transported to the organ where blood is required. For this reason the spleen is also called the blood bank of human body.
2. Filtration of blood - Spleen filters the blood & removes the old & dead RBCs. It acts like a maze from which healthy RBCs can easily pass while the old & dead RBCs get stuck in it. These are then broken down in the spleen by macrophages. For this reason the spleen is also called as The Graveyard of RBCs.

Additional Information 

Heart:

• The heart is a mesodermally derived organ, that is present in the thoracic cavity, in between the two lungs, slightly tilted to the left. It has the size of a clenched fist. It is protected by a double-walled membranous bag, pericardium, enclosing the pericardial fluid.

Liver:

• The liver is the largest gland of the human body. It performs the function of detoxification of harmful substances in the body
• For example, it converts harmful ammonia into urea,  It also breaks down alcohol and other such substances in the blood. 

Bone marrow :

• Bone marrow refers to the tissue located in the hollow interior of long bones. It is composed of adipose tissue, areolar tissue, and blood cells.
• Bone marrow is mainly of two types – red and yellow

Just as Needle is a part/component of the Clock, similarly Blade is a part/component of Fan.

Thus the related word pair is Fan : Blade.