WAEC Physics Past Questions & Answers - Page 82

406.

Which of the following instruments is used to determine the accurate value of the electromotive force of a cell?

A.

voltmeter

B.

meterbridge

C.

voltameter

D.

potentiometer

Correct answer is D

No explanation has been provided for this answer.

407.

A potential difference of 12V is applied across the ends of a 6\(\Omega\) resistor for 10 minutes. Determine the quantity of heat generated

A.

720J

B.

1200J

C.

14400J

D.

43200J

Correct answer is C

Q = \(\frac{V^2 t}{R}

= \frac{12^2 \times 10 \times 60}{6}\)

= 14400J

408.

A charge of 2.0 x 10\(^{-5}\) C experiences a force of 80N in a uniform electric field. Calculate the magnitude of the electric field intensity

A.

8.0 x 106 NC-1

B.

4.0 x 106 NC-1

C.

4.0 x 104 NC-1

D.

2.0 x 104 NC-1

Correct answer is B

E = \(\frac{F}{Q} = \frac{80}{2 \times 10^{-5}}\)

= 4 x 10\(^6\) NC\(^{-1}\)

409.

When a person holds a negatively charges metal rod and stands bare-footed on the ground, how will the charges leak?

A.

negative charges flows to the ground through the person's body

B.

positive charges flow from the ground through his body to neutralize the negative charges

C.

positive charges in the air neutralizes the negative charges the person is holding

D.

negative charges will leak through the air

Correct answer is A

No explanation has been provided for this answer.

410.

Which of the following statements about waves in pipes is correct?

A.

for open pipes, there is only one end correction to be accounted for

B.

for closed pipes, there are two end corrections to be accounted for

C.

only odd harmonics are possible in closed pipes

D.

all harmonics are possible in closed pipes

Correct answer is C

No explanation has been provided for this answer.