Electromagnetic Induction - Jamb Physics Past Questions and Answers

Question 21:

• JAMB 2008

I. for current amplification.
II. for voltage stabilization.
III. for power amplification.
IV. as a switch.
which of the above are the uses of transistor?

A. I,II,III and IV
B. I,III, and IV only
C. I, II and III only
D. I,II and IV only

Question 22:

• JAMB 2012

In fleming's right-hand rule, the thumb, the forefinger and the middle finger if held mutually at right angles represent respectively, the

A. Motion, the field and the induced current
B. Induced current, the motion and the field
C. Field, the induced current and the motion
D. Induced current, the field and the motion

Question 23:

• JAMB 2012

An electron of charge 1.6 x 10^-19C and mass 9.1 x 10^-31kg is accelerated between two metal plates with a velocity of 4 x 10⁷ms^-1, the potential difference between the plates is

A. 4.55 x 10³V
B. 4.55 x 10²V
C. 9.10 x 10¹V
D. 4.55 x 10¹V

Question 24:

• JAMB 2013

Induced emfs are best explained using

A. Ohm's law
B. Faraday's law
C. Colomb's law
D. Lenz's law

Question 25:

• JAMB 2015

The strength of an electromagnet increase with

A. Increase in the number of turn of the coil
B. Decrease in current with the coil
C. Increase in the distance between the pole
D. Increase in current without the coil