Physics Past Questions and Answers

Calculate the energy stored in a 20\(\mu F\) capacitor. If the p.d between the plates is 40V

A 3.2 x 10^-2J
B 1.6 x 10^-2J
C 8.0 x 10^-4J
D 4.0 x 10^-4J

Question 992:

Given that the gravitational constant is G. Newton's universal law of gravitation states that the force of attraction between two masses M₁ and M₂ separation by a distance r is

A \(Gr^2 M_1M_2\)
B \(Gr M_1M_2\)
C \(\frac{GM_1 M_2}{r^2}\)
D \(\frac{GM_1 M_2}{r}\)

Question 993:

A charge of 1.6 x 10^-10C is placed in a uniform electric field of intensity 2.0 x 10⁵ NC^-1. calculate the magnitude of the electric force exerted on the change

A 3.2 x 10⁵N
B 1.8 x 10⁵N
C 3.2 x 10^-5N
D 1.8 x 10^-5N

Question 994:

Which of the following statements is not correct?

A A magnetic field is a region in which a magnetic force will be detected
B A magnetic line of force is a path along which a magnetic fields are scalar quantities it were free
C Magnetic fields are scalar quantities
D Neutral point are obtained where the earth's magnetic force is exactly equal and opposite to that due to a magnet

Question 995:

The main function of the mouth piece of a telephone is that it converts sound energy to

A Mechanical energy
B Electrical energy
C Chemical energy
D Thermal energy