WAEC Physics Past Questions & Answers - Page 277

1,381.

Calculate the escape velocity of a satellite launched from the earth’s surface (Take g as 10ms-2 and the radius of the earth as 6.4 x 106m)

A.

8.00 x 106ms-1

B.

1.13 x104ms-1

C.

3.58x102ms-1

D.

5.59 x10-2ms-1

E.

3.95x10-2ms-1

Correct answer is B

V = 2gr

= 2 x 10 x 6.4 x 106

1.13 x 104ms-1

1,382.

A household refrigerator consumes electrical energy at the rate of 200 W. lf electricity costs 5 k per kWh, calculate the cost of operating the appliance for 30 days.

A.

N7.20

B.

N12.00

C.

N30.00

D.

N33.33

E.

N72.00

Correct answer is A

E = 200 x 30 x 24 Wh = 144000; Wh = 144KWh
Cost 144 x 5k = N7.20

1,383.

The unit of inductance is

A.

farad

B.

henry

C.

hertz

D.

weber

E.

tesla

Correct answer is B

No explanation has been provided for this answer.

1,384.

Which of the following instruments can be used to compare the relative magnitude of similar charges on two given bodies?

A.

Electrophorus

B.

Ebonite rod

C.

Proof plane

D.

Gold-leaf electroscope

E.

Capacitor

Correct answer is D

No explanation has been provided for this answer.