Jamb Physics 1985 Past Questions and Answers

Question 36:

• 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 37:

• 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 38:

• 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 39:

• 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

Question 40:

• JAMB 1985

An electric kettle, connected to a 240V mains, produces 6.0 x 10⁵J of heat energy to boil a quantity of water in 5 minutes. Find the resistance of the kettle.

A. 14.4\(\Omega\)
B. 28.8\(\Omega\)
C. 144\(\Omega\)
D. 288\(\Omega\)
E. 2880\(\Omega\)