JAMB Physics Past Questions & Answers - Page 272

1,356.

Which of the following is an essential physical property of the wires used for making fuses?

A.

low density

B.

high thermal conductivity

C.

low electrical resistivity

D.

low melting point

Correct answer is D

No explanation has been provided for this answer.

1,357.

The total energy required to send a unit positive charge round a complete electrical circuit is the

A.

kinetic energy

B.

potential difference

C.

electromotive force

D.

electrical energy

Correct answer is B

No explanation has been provided for this answer.

1,358.

When a known standard resistor of 2\(\Omega\) is connected to the 0.0cm end of a meter bridge, the balance point is found to be at 55.0cm. What is the value of the unknown resistor?

A.

1.10\(\Omega\)

B.

1.64\(\Omega\)

C.

2.44\(\Omega\)

D.

27.50\(\Omega\)

Correct answer is B

\(\frac{R_1}{R_2}\) = \(\frac{L_1}{R_2}\)

\(\frac{2}{R_2}\) = \(\frac{55}{45}\)

R = 1.64\(\Omega\)

1,359.

Three cells each of e.m.f. 1.5v and an internal resistance of 1.0\(\Omega\) are connected in parallel across a load resistance of 2.67\(\Omega\). Calculate the current in the load?

A.

0.26A

B.

0.41A

C.

0.50A

D.

0.79A

Correct answer is C

E = 1.5v

rT = \(\frac{1 \times 1\times 1}{(1\times1)+ (1\times1) +(1\times1)}\)

E.m. f = I(R + r) = 0.33\(\Omega\)

1.5 = I(2.67 + 0.33)

I = 0.5A

1,360.

Which of the following is a vector?

A.

Electric charge

B.

Electric field

C.

Electrical potential difference

D.

Electrical capacitance

Correct answer is B

No explanation has been provided for this answer.