Unit 3

What is the principle of operation of a PN junction diode?

• It conducts only when reverse biased.

• It conducts only when forward biased.

• It conducts under both forward and reverse bias.

• It does not conduct under any condition.

Which of the following components is NOT part of the block diagram of a DC power supply?

• Transformer

• Rectifier

• Zener diode

• Filter

What is the role of the transformer in a DC power supply?

• To regulate the output voltage

• To convert AC voltage to DC

• To step up or step down the AC voltage

• To convert the DC output to AC

In a full-wave bridge rectifier, how many diodes are used?

• 1

• 2

• 3

• 4

What is the purpose of a capacitor filter in a rectifier circuit?

• To convert DC to AC

• To smooth the pulsating DC output

• To reduce the current

• To increase the voltage

What is the main application of a Zener diode?

• To act as a rectifier

• To regulate voltage in a circuit

• To amplify signals

• To store energy

Which of the following is the main purpose of a 78xx series voltage regulator?

• To increase the voltage

• To provide a fixed positive voltage output

• To step up the current

• To rectify AC voltage

What is the function of the 79xx series voltage regulators?

• To provide a fixed negative voltage output

• To provide a fixed positive voltage output

• To regulate current

• To filter the output voltage