JAMB Physics Past Questions & Answers - Page 336

1,677.
1,678.

A particle carrying a charge of 1. 0 x 10-8C enters a magnetic field at 3.0x 10-2 ms -1 at right angles to the field. If the force on this particle is 1.8 x 10-8N, what is the magnitude of the field?

A.

6.0x10-1T

B.

6.0x10T

C.

6.0x10-3T

D.

6.0x10-4T

Correct answer is B

B = \(\frac{F}{QV}\)

B = \(\frac{1.8 \times 10^{-8}}{1.0 \times 10^{-8} \times 3.0 \times 10^{-2}}\)

1,679.

The fuse in an electric device is always connected to the

A.

neutral side of an electric supply

B.

earth side of an electric supply

C.

live side of an electric supply

D.

terminal side of an electric supply

Correct answer is C

No explanation has been provided for this answer.

1,680.

A newly charged 12V accumulator can easily start a car whereas eight new dry cells in series with a effective e.m.f. of 12V cannot start the same car because

A.

The current capacity is high

B.

The current capacity is low

C.

it cannot be re-charged

D.

it cannot easily be connected to a car

Correct answer is B

No explanation has been provided for this answer.