Question Detail

If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states this ?

Newton first law
Newton second law
Newton third law
Principle of conservation of linear momentum

Answer: Option D

1. Name of the instrument to measure atomspheric pressure ?

Barometer
Barograph
Bolometer
Callipers

Answer: Option A

Explanation:

Barograph - Recordings of atmospheric pressure,
Bolometer - Used to measure heat radiation,
Callipers - Used to measure inner and outer diameters of bodies.

2. All planets move around the sun in elliptical orbits, with the sun being at rest at one focus of the orbit.

True
False

Answer: Option A

3. Which instrument is used to measure pressure of gases ?

Manometer
Machmeter
Magnetometer
Micrometer

Answer: Option A

Explanation:

Machmeter - is used to determine the speed of an aircraft in terms of speed of sound,

Magnetometer - is used to compare magnetic movements and fields,

Micrometer - is used to convert sound waves into electrical vibrations.