JAMB Physics Past Questions & Answers - Page 320

1,596.

At what respective values of X, Y and Z would the unit of force, the newton, be dimensionally equivalent to MxLyTz?

A.

-1, 1, 2

B.

1, 1, -2

C.

1, -1, 2

D.

-1, 1, -2

Correct answer is B

F = m (v-u)

= kg x m x S-2

= M1L1T-2

1,597.

In photoelectric effect, electrons will leave the metal surface when illuminated by light of appropriate frequency if the photon energy is

A.

greater than the work function

B.

less than the work function

C.

equal to the work function

D.

equal to the maximium kinetic energy of the electron

Correct answer is A

No explanation has been provided for this answer.

1,598.

In a nuclear fusion experiment, the loss of mass amounts to 1.0 x 10-6kg. The amount of energy obtained from the fusion is

A.

3.0 x 10-4J

B.

3.0 x 10-1J

C.

9.0 x 104J

D.

9.0 x 1010J

Correct answer is D

Energy = mc2

= 1 x (3 x 108)2 x 106

= 9 x 1010J

1,599.

The electrochemical equivalent of a metal is 1.3 x 10-7kgC-1. The mass of the metal which 2.0 x 104C of electricity will deposit from a suitable electrolyte is

A.

6.5 x 10-2kg

B.

2.6 x 10-2kg

C.

6.5 x 10-3kg

D.

2.6 x 10-3kg

Correct answer is D

m = QZ

= 2 x 104 x 1.3 x 10-7

= 2.6 x 10-3kg