NEET Physics: Semiconductor diode I-V characteristics Practice Questions
13 free multiple-choice questions on Semiconductor diode I-V characteristics (Semiconductors) for NEET Physics, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. When a semiconductor diode is connected in forward bias, the primary effect observed is:
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Correct answer: A — The forward current increases significantly
In forward bias, the applied positive voltage reduces the potential barrier, allowing a large current to flow easily through the diode, which is the basis of conduction.
Q2. What happens to the current flowing through a diode when it is strongly reverse biased, assuming the diode is not in avalanche breakdown?
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Correct answer: D — The current remains zero (ideally)
When reverse biased, the diode acts as an open circuit, and ideally, no current flows across the junction.
Q3. The ideal diode model assumes that the diode acts as an open circuit when reverse biased. This ideal behavior is characteristic of which region?
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Correct answer: C — Reverse bias region
The reverse bias region is characterized by extremely high impedance, making the diode behave like an open circuit.
Q4. What physical phenomenon creates the potential barrier across the PN junction diode?
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Correct answer: A — Depletion region barrier
The potential barrier that governs the diode's behavior is established by the charge separation in the depletion region, known as the depletion region barrier.
Q5. At room temperature, the theoretical turn-on voltage (cut-in voltage) for a silicon diode is approximately:
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Correct answer: B — 0.7 V
The typical knee voltage or turn-on voltage for a standard silicon diode operating at room temperature is around 0.7 V.
Q6. Which region of the diode I-V curve corresponds to the forward bias operation of a semiconductor diode?
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Correct answer: B — The region where current flows easily
Forward bias operation occurs when the anode is positive with respect to the cathode, leading to current flow through the diode.
Q7. The diode characteristic curve is primarily used to determine which parameter of the diode?
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Correct answer: D — Diode forward voltage drop
The I-V characteristics directly show the relationship between the applied voltage and the resulting current, which is crucial for calculating voltage drops.
Q8. In the reverse bias region of a PN junction diode, what happens to the diode's resistance?
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Correct answer: A — It increases
In reverse bias, the diode acts as an open circuit (an insulator), and its resistance becomes very high (ideally infinite), thus increasing.
Q9. If a diode is reverse-biased beyond its breakdown voltage, what is the resulting characteristic behavior?
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Correct answer: D — Avalanche effect leading to high current
When the reverse voltage exceeds the breakdown limit, avalanche multiplication occurs, leading to a significant, non-zero reverse current flow.
Q10. The P-N junction diode is fundamentally important in semiconductor devices because it exhibits:
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Correct answer: B — Non-linear I-V characteristics
The non-linear I-V characteristics (exponential relationship) are essential as they allow the diode to act as a one-way valve for current, which is the foundation of rectification.
Q11. When a diode is operated in the forward bias region, the voltage across the diode must be greater than what value for significant current flow to occur?
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Correct answer: C — The knee voltage (cut-in voltage)
For current to flow, the applied forward voltage must exceed the diode's specific knee voltage (or cut-in voltage), beyond which current flows exponentially.
Q12. The I-V characteristic curve for a forward-biased diode is primarily characterized by which relationship?
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Correct answer: B — Exponential increase
In the forward bias region, the current increases exponentially with the applied voltage once the knee voltage is surpassed.
Q13. In reverse bias operation of a diode, the diode primarily functions as:
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Correct answer: A — An open circuit
In reverse bias, the applied negative voltage increases the potential barrier, effectively blocking the flow of majority carriers and causing the diode to behave like an open circuit.
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