A Zener diode is primarily used for

 Q: A semiconductor diode acts as a/an

Options:
A) Rectifier
B) Amplifier
C) Oscillator
D) Modulator
Answer: A) Rectifier
Explanation:
A diode allows current to flow only in one direction (forward bias), thus converting AC into DC — this process is called rectification.

---

2️⃣

Q: The resistance of a forward-biased diode is
Options:
A) Very high
B) Very low
C) Infinite
D) Equal to reverse resistance
Answer: B) Very low
Explanation:
In forward bias, the potential barrier decreases, allowing current to flow easily. Hence, the resistance is very low.

---

3️⃣

Q: The region around the p–n junction devoid of free charge carriers is called
Options:
A) Conduction region
B) Depletion region
C) Neutral region
D) Diffusion region
Answer: B) Depletion region
Explanation:
When a p–n junction forms, electrons and holes recombine near the junction, creating a region without free carriers — the depletion region.

---

4️⃣

Q: In a silicon diode, the forward voltage drop is approximately
Options:
A) 0.3 V
B) 0.5 V
C) 0.7 V
D) 1.0 V
Answer: C) 0.7 V
Explanation:
For silicon diodes, about 0.7 V is needed to overcome the barrier potential for conduction.

---

5️⃣

Q: In reverse bias, the current through a semiconductor diode is due to
Options:
A) Majority carriers
B) Minority carriers
C) Both majority and minority carriers
D) Surface current
Answer: B) Minority carriers
Explanation:
In reverse bias, the depletion region widens, and only minority carriers contribute to a small leakage current.

---

6️⃣

Q: The reverse current in a diode is typically of the order of
Options:
A) Milliamperes
B) Microamperes
C) Amperes
D) None
Answer: B) Microamperes
Explanation:
The reverse leakage current is very small (in μA range) because only minority carriers are involved.

---

7️⃣

Q: The diode that conducts in both directions is called
Options:
A) Zener diode
B) Tunnel diode
C) Varactor diode
D) LED
Answer: B) Tunnel diode
Explanation:
A tunnel diode exhibits negative resistance and allows conduction in both directions due to heavy doping and tunneling effect.

---

8️⃣

Q: A Zener diode is primarily used for
Options:
A) Rectification
B) Voltage regulation
C) Oscillation
D) Switching
Answer: B) Voltage regulation
Explanation:
Zener diodes operate in the breakdown region with nearly constant voltage, hence used for voltage regulation.

---

9️⃣

Q: The process of adding impurity atoms to a semiconductor is known as
Options:
A) Amplification
B) Doping
C) Diffusion
D) Ionization
Answer: B) Doping
Explanation:
Doping increases the conductivity of semiconductors by adding impurities that create majority charge carriers.

---

10️⃣

Q: When a diode is forward-biased, the width of depletion region
Options:
A) Increases
B) Decreases
C) Remains constant
D) Becomes infinite
Answer: B) Decreases
Explanation:
Forward bias reduces the potential barrier, causing the depletion region to shrink and allowing current to flow easily.