Question 511:

• JAMB 1988

When a resistance R is across a cell, the voltage across the terminals of the cell is reduced to two-third of its normal value. The internal resistance of the cell is

A. \(\frac{2}{1}\)R
B. \(\frac{1}{2}\)R
C. \(\frac{3}{2}\)R
D. 5R

Question 512:

• JAMB 1988

A household refrigerator is rated 200 watts. If electricity costs 5k per kWh, what is the cost of operating it in 20 days?

A. N4.80
B. N48.00
C. N480.00
D. N4800.00

Question 513:

• JAMB 1988

Which of the following ammeters may be used to measure alternating currents? i. moving-coil ammeter ii. moving-iron ammeter iii. hot-wire ammeter

A. I and ii only
B. Ii and iii only
C. I and iii only
D. I, ii, and iii

Question 514:

• JAMB 1988

The principle of operation of an induction coil is based on

A. Ohm's law
B. Amphere's law
C. Faraday's law
D. Columbs law

Question 515:

• JAMB 1988

A dynamo primarily combines

A. Mechanical energy into electrical energy
B. Electrical energy into kinetic energy
C. Potential energy into kinetic energy
D. Kinetic energy into potential energy