WAEC Past Questions and Answers - Page 4126

20,626.

What is the potential difference between X and Y in the diagram above if the battery is of negligible internal resistance

A.

12.5V

B.

5.8V

C.

5.0V

D.

3.0V

E.

2.0V

Correct answer is D

No explanation has been provided for this answer.

20,628.

Calculate the quantity charge flowing through a conductor if a current of 10A passes through the conductor for 10s.

A.

100C

B.

20C

C.

15C

D.

10C

E.

1C

Correct answer is A

No explanation has been provided for this answer.

20,629.

The effective capacitance between points X and Y in the diagram below is 1.0μF, What is the value of the capacitance C, measured in micro-farad?

A.

5.0μF

B.

4.0μF

C.

3.0μF

D.

1.0μF

E.

0.5μF

Correct answer is D

No explanation has been provided for this answer.

20,630.

The energy stored in a capacitor of capacitance 5μF is 40J. Calculate the voltage applied across its terminals?

A.

4000V

B.

200V

C.

16V

D.

6V

E.

4V

Correct answer is A

\(E = \frac{CV^{2}}{2}\)

\(V^{2} = \frac{2E}{C}\)

\(V^{2} = \frac{2\times 40}{5 \times 10^{-6}}\)

\(V^{2} = 16 \times 10^{6}\)

\(V = 4 \times 10^{3} = 4000v\)