Question Detail

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

1. 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.

2. What is refractive index ?

it is defined as the ratio of speed of light in the medium to the speed of light in vacuum.
it is defined as the ratio of speed of light in vacuum to the speed of light in the medium .
it is defined as the product of speed of light in medium and in vacuum.
None of above

Answer: Option B

3. Which is true

In a static liquid at same horizontal level, pressure is more at centre
In a static liquid at same horizontal level, pressure is less at centre.
In a static liquid at same horizontal level, pressure is same at all points
In a static liquid at same horizontal level, pressure is different at all points

Answer: Option C

4. Which instrument is used to measure the scattering of light by particles suspended in a liquid ?

Nephetometer
Ohmmeter
Ondometer
Pyrometer

Answer: Option A

Explanation:

Ohmmeter - is used to measure electrical resistance in ohms,

Ondometer - is used to measure frequency of electromagnetic waves,

Pyrometer - is used to measure very high temperature.