NECO Physics Past Questions & Answers - Page 50

246.

Which colour is deviated least when white light passes through a triangular prism?

A.

green

B.

indigo

C.

red

D.

violet

E.

yellow

Correct answer is C

violet color will deviate the most.

Red light shows the least amount of deviation

247.

The ability of the eye to focus on objects at various distances is known as

A.

accommodation

B.

astigmatism

C.

eye ring

D.

myopia

E.

presbyopia

Correct answer is A

No explanation has been provided for this answer.

248.

In an operating X-ray tube, a high p.d is applied between the cathode and the anode for the purpose of

A.

accelerating the electrons to a very high energy

B.

concentrating electrons on the target

C.

heating the anode

D.

heating the cathode

E.

producing a stream of electrons

Correct answer is A

No explanation has been provided for this answer.

249.

In 24 days a radioactive isotope decreases in mass from 128g to 2g. What is the half-life of the radioactive material?

A.

2.54 days

B.

4.00 days

C.

4.80 days

D.

6.00 days

E.

8.00 days

Correct answer is B

No explanation has been provided for this answer.

250.

The magnetic effect of a current-carrying coil is NOT utilized in the making of a/an

A.

carbon microphone

B.

electric bells

C.

magnetic relay

D.

telephone earpiece

E.

thermostat

Correct answer is E

No explanation has been provided for this answer.