MCQs of Special purpose diodes and transistors (Basic Electronics - 3110016)

Showing 21 to 30 out of 38 Questions

21.

The major advantage of a phototransistor as compared to photo diode is its

(a)	Response to higher frequencies
(b)	AC operation
(c)	Increased sensitivity
(d)	Durability

22.

What is true about the breakdown voltage in a Zener diode?

(a)	It decreases when current increases
(b)	It destroys the diode
(c)	It equals the current times resistance
(d)	It is approximately constant

23.

Which of this is the best description of a Zener diode?

(a)	It is a rectifier diode
(b)	It is a constant voltage device
(c)	It is a constant current device
(d)	It works in the forward region

24.

The voltage across Zener resistance is usually

(a)	Small
(b)	Large
(c)	Measured in volts
(d)	Subtracted from the breakdown voltage

25.

If the series resistance increases in an unloaded Zener regulator, the Zener current

(a)	Decreases
(b)	Stays the same
(c)	Increases
(d)	Equals the voltage divided by resistance

26.

The load voltage is approximately constant when a Zener diode is

(a)	Forward biased
(b)	Reverse biased
(c)	Operating in the breakdown region
(d)	Unbiased

27.

In a loaded Zener regulator, which is the largest current?

28.

If the load resistance increases in a Zener regulator, the Zener current

(a)	Decreases
(b)	Stays the same
(c)	Increases
(d)	Equals the source voltage divided by the series resistance

29.

Which of the following will not indicate a Zener diode’s breakdown voltage?

30.

The capacitance of a varactor diode increases when the reverse voltage across it

Showing 21 to 30 out of 38 Questions