NECO Physics Past Questions & Answers - Page 40

196.

For which of the following sets are the units fundamental?

A.

Area, length and volume

B.

Impulse, mass and time

C.

Length, time and mass

D.

Velocity, distance and time

E.

Volume, mass and density

Correct answer is C

No explanation has been provided for this answer.

197.

A machine has an efficiency of 80%. If the machine is required to overcome a load of 60N with a force of 40N, calculate its velocity ratio.

A.

0.53

B.

0.83

C.

1.20

D.

1.50

E.

1.88

Correct answer is E

No explanation has been provided for this answer.

198.

Calculate the amount of heat generated in an external load of resistance 8Ω if an alternating current of peak value 5 A is passed through it for 100s.

A.

2.0 × 104J

B.

1.0 × 104J

C.

5.0 × 103J

D.

4.0 × 103J

E.

2.0 × 102J

Correct answer is A

No explanation has been provided for this answer.

199.

Evaporation of a liquid produces cooling of the liquid because the

A.

attraction between the vapour molecules and the liquid molecules is great

B.

average kinetic energy of the liquid is reduced

C.

density of the liquid decreases

D.

vapour pressure above the liquid rises

E.

volume of the liquid decreases

Correct answer is B

No explanation has been provided for this answer.

200.

Which of the following instruments can be used to measure e.m.f. most accurately.

A.

Ammeter

B.

Galvanometer

C.

Metre bridge

D.

Potentiometer

E.

Voltmeter

Correct answer is D

No explanation has been provided for this answer.