NEET Physics: Zener diode reverse breakdown voltage Practice Questions

Correct answer: B — Operating in the reverse saturation region

When operated below the breakdown voltage, the diode acts as an ideal reverse-biased diode, entering the reverse saturation region where it blocks current effectively.

Correct answer: A — Reverse breakdown state

When the reverse voltage reaches V_Z, the diode enters the Zener breakdown region, where it maintains a specific voltage regardless of small changes in current.

Correct answer: A — It decreases

The breakdown voltage is temperature-sensitive. As temperature increases, the material properties change, and the breakdown voltage generally decreases.

Correct answer: A — The doping concentration of the semiconductor material

The breakdown voltage (V_Z) is fundamentally dependent on the doping concentration of the P-N junction and the physical properties of the semiconductor material.

Correct answer: A — Series resistance

For practical applications, the material must offer a good trade-off. Silicon diodes offer a reasonable breakdown voltage while managing power dissipation and leakage currents effectively in basic regulatory setups.

Correct answer: C — Zener current (I_Z)

The specific current flowing through the diode when it is operating in the breakdown region is called the Zener current (I_Z).

Correct answer: A — Independent of the material composition

While V_Z has some dependence on temperature, for practical applications and standard ratings, it is considered a characteristic property determined by the material and doping, rather than being directly dependent on the instantaneous applied voltage level itself.

Correct answer: A — The reverse voltage above which breakdown occurs

The breakdown voltage is the specific reverse voltage level at which the Zener diode enters the breakdown region and begins to conduct reliably.

Correct answer: A — It conducts heavily in the forward direction

When the reverse voltage exceeds the breakdown voltage, the diode enters a state of avalanche breakdown. Operating significantly above V_Z changes the thermal stability and behavior, often leading to damage or operating outside intended specifications.

Correct answer: A — Breakdown region

The Zener effect results in a region where the voltage remains nearly constant (breakdown region) even as the current changes, which is the basis for Zener regulation.

Correct answer: C — Silicon (Si)

Silicon (Si) and Germanium (Ge) are the most commonly used semiconductor materials for manufacturing Zener diodes due to their suitable bandgap properties for this application.

Correct answer: C — Reverse biasing

Zener diode breakdown occurs when it is reverse biased, allowing the diode to conduct significantly under a specific reverse voltage.

Correct answer: B — Voltage regulation across a specific voltage

The defining characteristic exploited by the Zener diode is its ability to maintain a nearly constant voltage (V_Z) across its terminals when reverse-biased, making it useful for voltage regulation.