Question 836:

• JAMB 1995

The purpose of a dielectric material in a parallel plate capacitor is to

A. Increase its capacitance
B. Decrease its capacitance
C. Insulate the plate from each other
D. Increase the magnetic field between the plates

Question 837:

• JAMB 1995

An electric current of 2 amperes flows in a heating coil of resistance 50 ohms for 3 minutes 20 seconds. Determine the heat produced

A. 0.5kJ
B. 8.0kJ
C. 20.0kJ
D. 40.0kJ

Question 838:

• JAMB 1995

If the maximum voltage across a 100ohms resistor is 20V, then the maximum power it can dissipate is

A. 5.00W
B. 4.00W
C. 2.00W
D. 25W

Question 839:

• JAMB 1995

Which of the following is required to convert a milliammeter to an ammeter?

A. A high resistance in parallel
B. A high resistance in series
C. A low resistance in parallel
D. A low resistance in series

Question 840:

• JAMB 1995

The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be

A. 3V
B. 6V
C. 24V
D. 48V