Introductory Electronics - Jamb Physics Past Questions and Answers

Question 21:

• JAMB 2010

Transistors are used for the

A. Rectification of signals
B. Conversion of a.c to d.c
C. Amplification of signals
D. Conversion of d.c to a.c

Question 22:

• JAMB 2010

Which of the following is a pure semiconductor?

A. Carbon
B. Silicon
C. Transistor
D. Phosphorus

Question 23:

• JAMB 2011

The electrical properties of germanium can be altered drastically by the addition of impurity. This process is referred to as

A. Saturation
B. Bonding
C. Amplification
D. Dopping

Question 24:

• JAMB 2012

A semiconductor diode is used in rectifying alternating current into direct current mainly because it

A. Allows current to flow in either direction
B. Is non-linear
C. Offers a high input resistance
D. Allows current to flow only in one direction

Question 25:

• JAMB 2012

in a pure semiconductor, the number of electrons in the conduction band is

A. Less than the number of holes in the valence band
B. Equal to the number of holes in the valence band
C. Greater than the number of holes in the valence band
D. Twice the number of holes in the valence band