Physics (Part-3) (CDS-Solved Paper)

Total Questions: 6

1. No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be [Evening Shift-2014 (II)]

Correct Answer: (a) either plane or convex
Solution:

Image formed by a plane mirror and a convex mirror is always erect, irrespective of position of object.

2. A mobile phone charger is [Evening Shift-2014 (II)]

Correct Answer: (c) a step-down transformer
Solution:

A mobile phone charger is basically a step-down transformer. It converts high voltage of home supply to low voltage.

3. Two layers of a cloth of equal thickness provide warmer covering than a single layer of cloth with double the thickness. Why? [Evening Shift-2014 (II)]

Correct Answer: (a) Because of the air encapsulated between two layers
Solution:

Two layers of a cloth are warmer because air trapped between the layers acts as thermal insulator.

4. In cricket match, while catching a fast moving ball, a fielder in the ground gradually pulls his hands backwards with the moving ball to reduce the velocity to zero. The act represents [Evening Shift-2014 (II)]

Correct Answer: (b) Newton’s second law of motion
Solution:

5. When an incandescent electric bulb glows [Evening Shift-2014 (II)]

Correct Answer: (b) the electric energy is partly converted into light energy and partly into heat energy
Solution:

An incandescent electric bulb is an electric light with a wire filament heated to a high temperature. By passing an electric current through it, untill it glows with visible light. These bulbs convert less than 5% of the energy into visible light. The remaining energy is converted into heat.

6. You are asked to jog in a circular track of radius 35 m. Right one complete round on the circular track, your displacement and distance covered by you respectively [Evening Shift-2014 (II)]

Correct Answer: (a) zero and 220 m
Solution:

During jogging on a circular track, in complete round initial and final positions are same, therefore displacement is zero.