JAMB Physics Past Questions & Answers - Page 316

1,576.

The volume of an air bubble increases from the bottom to the top of a lake at constant temperature because

A.

atmospheric pressure acts on the surface of the lake

B.

pressure increases with depth

C.

density remains constant with pressure

D.

the bubble experiences an upthrust

Correct answer is B

No explanation has been provided for this answer.

1,577.

A hydraulic press has a large circular piston of radius 0.8m and a circular plunger of radius 0.2m. A force of 500N is exerted by the plunger. Find the force exerted on the piston

A.

8000N

B.

4000N

C.

2000N

D.

31N

Correct answer is A

Pressure on piston = pressure on the plunger

\(\frac{500}{\pi\ \times\ 0.2 \times\ 0.2}\) = \(\frac{F}{\pi\ \times\ 0.8 \times\ 0.8}\)

F = 8000N

 

1,578.

The energy contained in a wire when it extended by 0.02m by a force 500 N is

A.

5J

B.

10J

C.

103J

D.

104

Correct answer is A

Energy = \(\frac{1}{2}\)Fe

= \(\frac{1}{2}\) x 500 x 0.02

E = 5J

1,580.

A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed

A.

\(\frac{mv^2}{t}\)

B.

\(\frac{mv^2}{2t}\)

C.

\(\frac{mv}{t}\)

D.

\(\frac{mv}{2t}\)

Correct answer is A

No explanation has been provided for this answer.