JAMB Physics Past Questions & Answers - Page 440

2,196.

The diagram above shows a magnet X with its south pole moved along a soft - iron bar PQ in the direction shown. After some time, the poles at P and Q respectively are

A.

North - North

B.

North - South

C.

South - North

D.

South - South

Correct answer is B

No explanation has been provided for this answer.

2,197.

The diagram above shows the prism arrangement in a

A.

binocular

B.

spectrometer

C.

periscope

D.

projector

Correct answer is C

No explanation has been provided for this answer.

2,198.

In the J-tube above, Y and X are on the same horizontal level and 30cm3 of air is trapped above Y when the atmospheric pressure is 75cm Hg, calculate the volume of air trapped above Y when 15cm Hg is now poured into the limb above X

A.

15 cm3

B.

25 cm3

C.

35 cm3

D.

45 cm3

Correct answer is B

Since the temperature of the air is to remain Constant => P1V1 = P2V2
∴ 75 x 30 = (75 + 15) x V2
75 x 30 = 90 x V2

=> V2 = 75 x 30
_90

 

= 2250
_90


= 25cm2

 

2,199.

The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston

A.

both valves are open

B.

P is open while Q is closed

C.

P is closed while Q is open

D.

Both valves are closed

Correct answer is B

No explanation has been provided for this answer.

2,200.

The diagram above shows a solid figure with base PQ and center of gravity G on a inclined plane. Which of the following statements is correct

A.

The solid will fall over if the vertical line through G lies outside the base

B.

The solid will fall over if the vertical line through lies inside the base

C.

The solid will not fall over if the vertical line through G lies outside the base

D.

The solid can never fall over

Correct answer is A

The solid will fall over if when the vertical line through G lies outside the base, when slightly tilted