Question Detail

The rotational effect of a force on a body about an axis of rotation is described in terms of

Centre of gravity
Centripetal force
Centrifugal force
Moment of force

Answer: Option D

1. Which law states, "The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings."

Doppler's Effect
Newton's law of cooling
Kirchhoff's Law
Stefan's Law

Answer: Option B

Explanation:

Doppler's Effect - The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching and an apparent downward shift in frequency for observers from whom the source is receding.

Kirchhoff's Law - Kirchhoff's Law signifies that good absorbers are good emitters.

Stefan's Law - The radiant energy emitted by a black body per unit area per unit time is directly proportional to the fourth power of its absolute temperature.

2. If lift is going up with acceleration, the apparent weight of a body is

may be more or less than true weight
equal to the true weight
less than the true weight
more than the true weight

Answer: Option D

3. The rotational effect of a force on a body about an axis of rotation is described in terms of

Centre of gravity
Centripetal force
Centrifugal force
Moment of force

Answer: Option D

4. What is unit of Work and Energy ?

Joule
kilogram
amphere
meter

Answer: Option A

5. Which instrument is used to measure sound under water ?

Hygrometer
Hygroscope
Hypsometer
Hydrophone

Answer: Option D

Explanation:

Hygrometer - is used to measure level of humidity,

Hygroscope - shows the changes in atmospheric humidity,

Hypsometer - is used to determine the boiling points of liquids.