Diodes and Applications MCQs

Question 1

A diode for which you can change the reverse bias, and thus vary the capacitance is called a

Accepted Answer

varactor diode

Answer

tunnel diode

Answer

zener diode

Answer

switching diode

Question 2

A filtered full-wave rectifier voltage has a smaller ripple than does a half-wave rectifier voltage for the same load resistance and capacitor values because:

Accepted Answer

there is a shorter time between peaks

Answer

there is a longer time between peaks

Answer

the larger the ripple, the better the filtering action

Answer

none of the above

Question 3

Testing a good diode with an ohmmeter should indicate

Accepted Answer

high resistance when reverse biased and low resistance when forward biased

Answer

high resistance when forward or reverse biased

Answer

low resistance when forward or reverse biased

Answer

high resistance when forward biased and low resistance when reverse biased

Question 4

The peak inverse voltage (PIV) across a nonconducting diode in a bridge rectifier equals approximately:

Accepted Answer

the peak value of the secondary voltage

Answer

half the peak secondary voltage

Answer

twice the peak secondary voltage

Answer

four times the peak value of the secondary voltage

Question 5

Electrons in the outermost orbit or shell of an atom are called

Accepted Answer

valence electrons

Answer

free electrons

Answer

negative ions

Answer

conduction band electrons

Question 6

Shunting the ac component away from the load is the task of a:

Accepted Answer

filter

Answer

transformer

Answer

regulator

Answer

rectifier

Question 7

A pn junction allows current flow when

Accepted Answer

the p-type material is more positive than the n-type material

Answer

the n-type material is more positive than the p-type material

Answer

both the n-type and p-type materials have the same potential

Answer

there is no potential on the n-type or p-type materials

Question 8

When a diode is forward biased, the voltage across it

Accepted Answer

remains approximately the same

Answer

is directly proportional to the current

Answer

is inversely proportional to the current

Answer

is directly proportional to the source voltage

Question 9

Why is heat produced in a diode?

Accepted Answer

due to current passing through the diode

Answer

due to voltage across the diode

Answer

due to the power rating of the diode

Answer

due to the PN junction of the diode