Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

151.

A bar magnet is divided into two pieces, which of the following statement is correct?

A.

two new magnets are created

B.

the magnetic field of each separate piece becomes stronger

C.

the electric field is created

D.

the bar magnet is demagnetized

Correct answer is A

When it is cut into two, the two cut pieces will have their own north and south poles.

152.

Which of these is a derived unit?

A.

Kilogram

B.

Metre

C.

Newton

D.

Second

Correct answer is C

Examples of Fundamental Quantities ; Mass, kilogram, kg ; Electric Current, ampere, A ; Temperature, kelvin, K ; Amount of Substance, mole, Mol.

153.

In which of the following situations is friction not useful?

A.

Operation of a grinding machine

B.

Walking

C.

Application of brakes

D.

Moving piston in a sleeve

Correct answer is D

 friction, force that resists the sliding or rolling of one solid object over another.

Examples of friction in our daily life

  • Driving of a a vehicle on a surface.
  • Applying brakes to stop a moving vehicle.
  • Skating.
  • Walking on the road.

154.

The basic principle of operation of a beam balance is-----------------

A.

Hooke's law

B.

Archimedes principle

C.

law of flotation

D.

principle of moments

Correct answer is D

Hooke's Law states that the extension of a spring is proportional to the load that is applied to it. A variety of materials obey this law as long as the load does not exceed the material's elastic limit.

Archimede's Principle states that a body immersed in a fluid experiences an upthrust equal to the weight of the fluid displaced, and this is fundamental to the equilibrium of a body floating in still water.

When a body floats in a liquid, the weight of the liquid displaced by its immersed part is equal to the total weight of the body. This is the law of floatation.

The Principle of Moments states that when a body is balanced, the total clockwise moment about a point equals the total anticlockwise moment about the same point.

155.

Using venier calipers, which of the following readings gives the correct measurement for the length of a rod?

A.

4.1 cm

B.

4.13cm

C.

125 cm

D.

1254 cm

Correct answer is B

Vernier calipers commonly used in industry provide a precision to 0.01 mm (10 micrometres), or 0.01cm or one thousandth of an inch.

 Usually, it is the total length of the main scale. Vernier calipers, generally, have a range of 300 mm

300 millimeters equal 30.0 centimeters (300mm = 30.0cm).