JAMB Physics Past Questions & Answers - Page 257

1,281.

In a certain fusion reaction, a deuteron (\(^{2}_{1}H\)) interacts with a triton (\(^{3}_{1}He\)) and produces an a-particle (\(^{4}_{2}He\)) and a second product. The second product is

A.

a proton

B.

an electron

C.

a neutron

D.

a gamma ray

Correct answer is C

\(^{2}_{1}H\) + \(^{3}_{1}H\) \(\to\) \(^{4}_{2}He\) + \(^{1}_{0}He\)

1,282.

A dynamo primarily combines

A.

mechanical energy into electrical energy

B.

electrical energy into kinetic energy

C.

potential energy into kinetic energy

D.

kinetic energy into potential energy

Correct answer is A

No explanation has been provided for this answer.

1,283.

The principle of operation of an induction coil is based on

A.

Ohm's law

B.

Amphere's law

C.

Faraday's law

D.

Columbs law

Correct answer is C

No explanation has been provided for this answer.

1,284.

Which of the following ammeters may be used to measure alternating currents?

i. moving-coil ammeter
ii. moving-iron ammeter
iii. hot-wire ammeter

A.

i and ii only

B.

ii and iii only

C.

i and iii only

D.

i, ii, and iii

Correct answer is D

No explanation has been provided for this answer.

1,285.

A household refrigerator is rated 200 watts. If electricity costs 5k per kWh, what is the cost of operating it in 20 days?

A.

N4.80

B.

N48.00

C.

N480.00

D.

N4800.00

Correct answer is A

Energy(kWhr) = 200 x 10-3 x 20 x 24

= 96kwhr

1 kwhr cost 5 kobo ; 96 kwhr will cost

5 x 96 = 480 kobo

= N4.80