Waec Physics 1990 Past Questions and Answers

Question 41:

• WAEC 1990

What is the electric potential energy between two protons each of charge q and at a distance of r apart? (Permittivity of free space = ε_o)

A. 4πε_oq²r
B. Qr/4πε_o
C. Q/4πε_or
D. Q²/4πε_or
E. Q²/4πε_or

Question 42:

• WAEC 1990

A work of 30 joules is done is transferring 5 millicoulombs of charge from a point B to a point A in an electric Held. The potential difference between B and A is

A. 1.7 x 10^-4V
B. 3.4x10^-4V
C. 1.5x10^-1V
D. 6.0 x10³V
E. 1.2 x10⁴V

Question 43:

• WAEC 1990

What is the value of R when G shows no deflection in the circuit illustrated above?

A. 80Ω
B. 75Ω
C. 45Ω
D. 20Ω
E. 10Ω

Question 44:

• WAEC 1990

A charge of 1.0 x 10^-5 Coulombs experience force of 40N at a certain point in space. What is the electric field intensity?

A. 8.00 x 10⁶NC^-1
B. 4.00 x 10⁶NC^-1
C. 4.00 x 10^-4NC^-1
D. 2.00 x 10^-4NC^-1
E. 2.50 x 10^-1NC^-1

Question 45:

• WAEC 1990

If the frequency of the ac. circuit illustrated above is 500/π Hz what would be the reactance in the circuit?

A. 0.0009Ω/π
B. 100Ω
C. 1030Ω
D. 1400Ω
E. 2500Ω