WAEC Physics Past Questions & Answers - Page 243

1,211.

The parts of a bar magnet at which the magnetic effect is strongest are called the

A.

poles

B.

neutral points

C.

magnetic declinations

D.

magnetic meridians

Correct answer is A

No explanation has been provided for this answer.

1,212.

Using the diagram above, calculate the effective capacitance of the circuit

A.

1.56μf

B.

3.00μF

C.

3.71μF

D.

9.00μF

Correct answer is D

No explanation has been provided for this answer.

1,213.

Using the data on the diagram above, calculate the potential difference across the 20- Ω resistor. (Neglect the internal resistance of the cell)

A.

5V

B.

10V

C.

20V

D.

60V

Correct answer is D

Voltage across 5Ω resistor = IR = 2 × 5 = 10V
Since voltage in a parallel connection is the same, voltage across 10Ω is also 10V
Current flowing across the 10Ω resistor

I = V/R = 10/10

Current I= 1A


Total current flowing = 2 + 1 = 3A


Voltage across 20Ω resistor = IR

= 3 × 20

= 60V

1,214.

Thunder is usually heard some seconds after lightning is observed because

A.

the human eye is more sensitive to light than the ear to sound

B.

sound and light travel in different media

C.

thunder occurs after lightning

D.

light travels faster than sound

Correct answer is D

No explanation has been provided for this answer.