NECO Physics Past Questions & Answers - Page 45

221.

What is stored by a dry Leclanhé cell?

A.

chemical energy

B.

heat energy

C.

mechanical energy

D.

nuclear energy

E.

solar energy

Correct answer is A

No explanation has been provided for this answer.

222.

An object is projected with a velocity of 50ms-1 from ground level at an angle θ to the vertical. If the total time of flight of the projectile is 5s, what is the value of θ? (g = 10ms-2)

A.

B.

30°

C.

45°

D.

60°

E.

90°

Correct answer is D

Time of flight =\( \frac{2Usin\theta}{g}\)

T = 5, g = 10m/s2

\(5 = \frac {2\times 50sin\theta}{10}\)

\(sin\theta =\frac {50}{100}\)

\(\theta = 30\)

vertical angle = 90 - 30 = 60°

223.

Which radiation is emitted when a beam of fast moving cathode rays is stopped by a heavy element?

A.

Alpha rays

B.

Gamma rays

C.

Positive rays

D.

Ultraviolet rays

E.

X-rays

Correct answer is E

No explanation has been provided for this answer.

224.

The use of electrical fuses in domestic wiring is

A.

to prevent and electrical shock

B.

to supply electricity to all the electrical appliances

C.

to allow electricity to flow easily through the mains to all the circuits

D.

to cut off the mains supply it too high a current flows

E.

to fuse all the circuit into one

Correct answer is D

No explanation has been provided for this answer.

225.

What does NOT affect the rate of evaporation of a liquid

A.

exposed surface area of the liquid

B.

humidity of the surroundings

C.

nature of the liquid

D.

temperature the liquid

E.

volume of the liquid.

Correct answer is E

No explanation has been provided for this answer.