NEET Physics: Zener diode as a voltage regulator Practice Questions

Correct answer: D — Zener breakdown voltage

The regulation mechanism in a Zener diode regulator relies entirely on the Zener diode's unique property of maintaining a nearly constant voltage across it when operating in its breakdown region (Zener breakdown voltage, V_Z).

Correct answer: A — The reverse voltage applied across the diode

The Zener breakdown voltage (V_Z) is the specific reverse voltage at which the diode begins to conduct significantly in breakdown mode, which is dependent on the material properties and applied voltage.

Correct answer: C — Zener Diode

The Zener diode is the active element that maintains the regulated output voltage by absorbing excess current when the input voltage changes.

Correct answer: A — To limit the current flowing through the Zener diode and protect it

The series resistor limits the total current entering the circuit, which is crucial for controlling the power dissipation and ensuring the Zener diode operates safely within its specified range.

Correct answer: B — Zener breakdown

The Zener diode operates based on the Zener breakdown effect, where a specific reverse voltage causes a large, stable current flow, which is the basis of voltage regulation.

Correct answer: A — b the output voltage remains constant irrespective of load variations

The defining feature of a Zener regulator is its ability to maintain a nearly constant output voltage across a varying load, provided the load current is within safe limits.

Correct answer: B — To limit the current through the Zener diode and protect the circuit

The series resistor limits the total current flowing into the circuit, which is crucial for protecting the Zener diode from excessive current and ensuring proper regulation under varying load conditions.

Correct answer: B — c to maintain a constant output voltage

The primary function of the Zener diode is to maintain a stable, constant voltage across its terminals, regardless of small fluctuations in the input voltage or load current.

Correct answer: D — Zener breakdown

Voltage regulation in Zener circuits relies on the controlled operation of the Zener diode in its reverse breakdown region, where it maintains a nearly constant voltage despite variations in the input voltage or load current.

Correct answer: C — Zener breakdown voltage (V_Z)

The operation of a Zener diode as a voltage regulator is based on the onset of the Zener breakdown effect, which occurs at the Zener voltage (V_Z).

Correct answer: B — Zener breakdown

The Zener diode relies on its controlled avalanche breakdown property in the reverse direction to maintain a constant voltage across it, irrespective of moderate changes in current or applied voltage.

Correct answer: B — A nearly constant voltage across a variable current

The defining characteristic of the Zener region is that the voltage across the diode remains nearly constant (the Zener voltage, V_Z) even as the current flowing through it changes, providing stable regulation.

Correct answer: A — Reverse saturation

When operated below V_Z, the diode behaves like a standard reverse-biased diode, where the current flow is very small, and it does not exhibit the stable breakdown characteristics.

Correct answer: D — To provide a stable reference voltage

The Zener diode is intentionally designed to maintain a nearly constant voltage across it when operated in the breakdown region, thus providing a stable reference voltage.

Correct answer: B — c avalanche breakdown

The Zener diode operates based on the Zener effect, which is a quantum mechanical phenomenon where a large reverse voltage causes a large reverse current, leading to breakdown.