Zener diodes

Question 1

At what point does a Zener diode allow current to flow?

Answer 1

When the reverse bias voltage reaches the Zener voltage level

Question 2

A Zener diode is particularly useful in circuits such as ? .

Answer 2

regulators

voltage stabilizers

Question 3

Zener diodes are manufactured to regulate voltages from ? to ? .

Answer 3

1.8v / 200v

Question 4

Zener diodes normally operate in forward bias mode.

Answer 4

false

Zener diodes normally operate in reverse bias mode.

Question 5

Which of the following is the correct symbol for a Zener diode?

Answer 5

cathode —z

Question 6

The illustration represents the characteristic curve for a(n) ? .

Answer 6

zener diode

Question 7

What is the voltage across the resistor?

Answer 7

Vr = Vs - Vz

The Zener is connected in a forward bias state and not in the normal reverse bias state for voltage regulation. Therefore, the calculation is approached as a normal diode. The typical value used for the voltage drop of a diode is 0.7 V.

Question 8

What is the current in the circuit? Calculate your answer to three decimal places.

Answer 8

Vr = Vs - Vz

I = Vr/Rs

Question 9

What are the most common voltage ratings for Zener diodes?

Answer 9

3.3v to 75v

Question 10

The output for the circuit is ? .

Answer 10

Diode is forward biased.

The correct answer is: 0.7 V

Question 11

The output for the circuit is ? .

Answer 11

The voltage source is not enough to turn on the Zener diode; therefore, the circuit acts as an open circuit (zero current).
The correct answer is: 5 V (source voltage)

Question 12

With the ON/OFF switch open, the current through the Zener and RS is ? .

Answer 12

Vr = Vs - Vz

Irs = Vz/Rs

Question 13

With the switch closed and RL set at 2,000 ohms, the current through RL is ? .

Answer 13

Irl = Vz/Rl

Question 14

With the switch closed and RL at 2,000 ohms, the current through the Zener diode is ? .

Answer 14

Iz = Irs - Irl

Question 15

A worker has several of each of the following values of Zener diodes: 4.7, 5.1, and 6.2 volts. He or she needs an output of 14.5 volts. What combination of three Zener diodes will provide the correct voltage?

Answer 15

two 4.7 and one 5.1

Question 16

Voltages equal to or greater than the Zener voltage define ? .

Answer 16

the Zener region

Question 17

The maximum power dissipation allowed before damage will occur to a Zener diode is abbreviated as PD(max).

Answer 17

true

Question 18

Kirchoff’s Voltage Law for the circuit can be written as

Vs + Vd3 + Vd2 + Vd1 + Vr1 = 0V

Answer 18

true

Question 19

What type of diode is commonly used in communications receivers where low-power high-frequency signals are required?

Answer 19

tunnel Diode

Question 20

What type of diode is used for switching circuits and microwaves?

Answer 20

Schottky diode

Shockley diode

Question 21

What type of diode is rated by its threshold (trigger) voltage?

Answer 21

Schottky diode

Question 22

What is a common use for a PIN diode?

Answer 22

Microwave

Modulator circuits as a switch

Radio frequency (RF)

Question 23

Which type of diode is used as a tank circuit tuning capacitor?

Answer 23

Varactor diode

Question 24

Which schematic symbol represents a Varactor diode?

Answer 24

up down circle around

Question 25

Which schematic symbol represents a Schottky diode?

Answer 25

—>Z— circle around