Question Detail

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.

1. Orbital speed of a satellite is dependent of its mass.

True
False

Answer: Option B

Explanation:

Orbital speed of a satellite is independent of its mass.

2. What is unit of Work and Energy ?

Joule
kilogram
amphere
meter

Answer: Option A

3. Which instrument is used to measure strength of direct current ?

Stroboscope
Streoscope
Tangent Galvanometer
Tachometer

Answer: Option C

Explanation:

Stroboscope - is used to view rapidly moving objects,

Streoscope - is used to view two dimensional pictures,

Tachometer - is used to determine rotational speed of a shaft (used in aeroplanes and motor boats).

4. What is escape velocity ?

Escape velocity is the maximum velocity with which a body should be projected from the surface of earth so it do not go beyond gravitational field of earth.
Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so it do not go beyond gravitational field of earth.
Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.
Escape velocity is the maximum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.

Answer: Option C

5. Which of the following is an electromagnetic wave ?

Cathode rays
Sound wave
Ultrasonic wave
Infra red rays

Answer: Option D