TRB Old Question Papers for Physics - 5

Question: 21

The principle employed in sonar is

(A) echo

(B) production of sound

(C) absorption of sound

(D) sound vibration

Question: 22

Unit of electrical energy is

(A) Ampere

(B) Joule

(C) Volt

(D) Hertz

Question: 23

The earth’s magnetic field always has a vertical component except at the

(A) Magnetic equator

(B) Latitude 45°

(C) Magnetic poles

(D) Geographic north pole

Question: 24

A mirror produces magnified erect image of an object. The nature of the mirror is

(A) Convex

(B) Concave

(C) Plane

(D) Neither concave nor convex

Question: 25

A 100 watt bulb is kept switched ON for four hours. The units of electrical energy consumed

(A) 0.4 unit

(B) 4 unit

(C) 25 unit

(D) 400 unit