Simple A. C. Circuits - Jamb Physics Past Questions and Answers

Question 16:

• JAMB 2004

The instrument used for securing a large number of similar charges by induction is called

A. Electrophorus
B. Capacitor
C. Proof-plane
D. Electroscope

Question 17:

• JAMB 2005

In an a.c circuit that contains only a capacitor, the voltage lags behind the current by

A. 180°
B. 90°
C. 60°
D. 30°

Question 18:

• JAMB 2005

If two inductors of inductances 3H and 6H are arranged in series, the total inductance is

A. 9.0H
B. 18.0H
C. 0.5H
D. 2.0H

Question 19:

• JAMB 2006

When an a.c. voltage is applied to a capacitor, no power is consumed because the current

A. Leads the voltage by 90°
B. Lags behind the voltage by 90°
C. And voltage are in phase
D. And voltage are 180° out of phase

Question 20:

• JAMB 2006

When a certain a.c supply is connected to a lamp, it lights with the same brightness as it does with a 12 V d.c battery. Then r.m.s value of the a.c supply is?

A. 12.0 V
B. 3.5 V
C. 17.0 V
D. 8.5