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. Force of attraction between the molecules of different substances is called

Surface tension
Cohensive force
Adhesive force
None of above

Answer: Option C

Explanation:

Cohensive force - Force of attraction between the molecules of same substance is called Cohensive force.

2. Nuclear sizes are expressed in a unit named

Fermi
Angstrom
Newton
Tesla

Answer: Option A

3. 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.

4. 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.