Question Detail

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.

1. Radian is used to measure

Temperature
Intensity of Flame
Angle
Solid Angle

Answer: Option C

Explanation:

Kelvin is used to measure Temperature,

Candela is used to measure Intensity of flame,

Steredian is used to measure Solid Angle.

2. What is newton third law of motion ?

Every body maintains its initial state rest or motion unless no external force is applied.
The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force.
To every action there is equal and opposite reaction.
None of above.

Answer: Option C

Explanation:

Newton First Law of Motion : Every body maintains its initial state rest or motion unless no external force is applied.

Newton Second Law of Motion : The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force.

3. What is unit of Work and Energy ?

Joule
kilogram
amphere
meter

Answer: Option A

4. Which instrument is used to measure heat radiation ?

Radar
Salinometer
Refractometer
Radio micrometer

Answer: Option D

Explanation:

Radar - is used to detect the direction and speed of an object by means of radiowaves,

Salinometer - is used to determine salinity of solutions,

Refractometer - is used to measure refractive indices.

5. Which instrument is used to record physical happenings at a distant place ?

Thermostat
Tonometer
Telemeter
Transponder

Answer: Option C

Explanation:

Thermostat - is used to regulate the temperature at a particular point.

Tonometer - is used to measure the pitch of a sound,

Transponder - is used to receive a signal and transmit a reply immediately.