(a) Electromagnetic Induction - Jamb Physics Past Questions and Answers

Question 16:

• JAMB 1997

In a purely inductive circuit, the current

A. Lags behind the voltage in phase by 90^o
B. Leads the voltage in phase by 90^o
C. Is in the same phase with the voltage
D. Leads the voltage by 180^o

Question 17:

• JAMB 1998

The iron core of an induction coil is made from bundles of wire so as to

A. Minimize eddy-currents
B. Generate eddy-current
C. Prevent sparking at the contact breaker
D. Get the greatest posible secondary voltage

Question 18:

• JAMB 1999

At what frequency would a 10H inductor have a reactance of 2000Ω?

A. π/200Hz
B. π/100Hz
C. 100/Ï€Hz
D. 100Ï€Hz

Question 19:

• JAMB 2000

If a charged ion goes through combined electric and magnetic fields, the resultant emergent velocity of the ion is

A. E/B
B. EB
C. B/E
D. E - B

Question 20:

• JAMB 2000

A 2H inductor has negligible resistance and is connected to a 50/Ï€ Hz A.C. Supply. The reactance of the inductor is

A. 200 Ω
B. 50 Ω
C. 100/π Ω
D. 25/π Ω