Light, Heat, Thermodynamics, Wave Motion, Sound, Optics & Oscillations - Category Wise Question And Answer Practice Test With Solutions

Question : 11 [IAS (Pre) 1995]

The normal temperature of human body on the Kelvin scale is

a) 290

b) 300

c) 280

d) 310

Question : 12 [IAS Prelim]

Assertion (A) :
A jet aircraft moving at Mach Number equal to 1 travels faster at an altitude of 15 km than while moving at Mach Number equal to 1 near the sea level.
Reason (R) :
The velocity of sound depends on the temperature of the surrounding medium.

a) Both A and R are true but R is not a correct explanation of A

b) Both A are R are true and R is the correct explanation of A

c) A is true but R is false

d) A is false but R is true

Question : 13

In scattering of light phenomenon, light falls on tiny particles absorbed by these tiny particles. Then these particles re-emit light in all directions.

1. Intensity of scattered light, $I ∝ 1/λ^4$
2. Greenish-blue appearance of sea water is due to scattering of light
3. In a clear atmosphere of the earth, red colour scatters more than blue colour.

a) 1 and 3

b) 1 and 2

c) 2 and 3

d) 1, 2 and 3

Question : 14 [UPPCS (Mains) 2007]

The technique used to transmit auto signals in television broadcasts is

a) Pulse Code Modulation

b) Frequency Modulation

c) Amplitude Modulation

d) Time Division Multiplexing

Question : 15 [BPSC (Pre) 1995]

In the night wind blows fast, dew is not formed because

a) Moisture in air is low

b) Temperature is high

c) Rate of evaporation is fast

d) Sky is not clear