Question 371:

• JAMB 1985

If the distance between two stationary charged particle is doubled, the magnitude of the electro-static force between them will be

A. Doubled
B. Halved
C. A quarter of its former value
D. Unchanged
E. Four times the original value

Question 372:

• JAMB 1985

Which of the following methods CANNOT be used to produce a steel magnet? The

A. Passing of an electric current through a solenoid
B. Repeated stroking of the specimen with a magnet
C. Repeated stroking of the specimen in opposite directions with magnets
D. Heating of the specimen
E. Hammering of the specimen in the earth's magnetic field

Question 373:

• JAMB 1985

A cell gives a current of 0.15A through a resistance of 8\(\Omega\) and 0.3A. When the resistance is changed to 3\(\Omega\) the internal resistance of the cell is

A. 0.05\(\Omega\)
B. 1.00\(\Omega\)
C. 1.50\(\Omega\)
D. 2.00\(\Omega\)
E. 2.50\(\Omega\)

Question 374:

• JAMB 1985

Which of the following will convert a milliammeter to a voltmeter?

A. Low series resistance
B. Low parallel resistance
C. High series resistance
D. High parallel resistance
E. Parallel resistance equal to milliammeter resistance

Question 375:

• JAMB 1985

A wire P has half the diameter and half the length of a wire Q of similar material. The ratio of the resistance of P to that of Q is

A. 8 : 1
B. 4 : 1
C. 2 : 1
D. 1 : 1
E. 1 : 4