Question 466:

• JAMB 1987

Two capacitance of 6\(\mu\)F and 8\(\mu\)F are connected in series. What additional capacitance must be connected in series with this combination to give a total of 3\(\mu\)F

A. 3\(\mu\)F
B. 16\(\mu\)F
C. 24\(\mu\)F
D. 30\(\mu\)F

Question 467:

• JAMB 1987

When a transformer has more secondary windings than primary windings, it

A. Has a smaller secondary current
B. Has a greater power output
C. Is a step-down transformer
D. Increases the total energy output

Question 468:

• JAMB 1987

A current of 0.5A flows through a resistor when connected to a 40-V battery. How much energy is dissipated in 2 minutes?

A. 1200J
B. 1500J
C. 2400J
D. 96000J

Question 469:

• JAMB 1987

The direction of the magnetic field at a point in the vicinity of a bar magnet is

A. Always towards the north pole of the magnet
B. Always away from the south pole of the magnet
C. Along the line joining the point to the neutral point
D. In the direction the north pole of a compass needle would point

Question 470:

• JAMB 1987

When two parallel wires carry currents in opposite directions, the force on either wire is

A. Away from the other wire
B. Zero, because the currents cancel each other
C. Twice as much as when the currents are in the same direction
D. Towards the other wire