Electronic Devices Important Questions for NEET Physics - 2026

1. Multiple choice questions.

1. Which of the following is not a property of a semiconductor?

• (a) Energy gap is very large
• (b) Conductivity increases with temperature
• (c) Resistivity decreases with increase of temperature
• (d) Used in electronic devices

Answer: (a) Energy gap is very large

2. The I-V characteristic of a p-n diode in forward bias is:

• (a) Linear
• (b) Non-linear and rises rapidly after a threshold
• (c) Constant
• (d) Zero everywhere

Answer: (b) Non-linear and rises rapidly after a threshold

3. Which logic gate outputs LOW only if all its inputs are HIGH?

• (a) OR gate
• (b) AND gate
• (c) NAND gate
• (d) NOR gate

Answer: (c) NAND gate

4. Which of the following devices is used as a voltage regulator?

• (a) LED
• (b) Zener diode
• (c) Solar cell
• (d) Photodiode

Answer: (b) Zener diode

2. Very Short Answer (VSA).

1. Define a semiconductor.

Answer: A semiconductor is a material whose electrical conductivity lies between that of a conductor and an insulator. Silicon and germanium are common examples.

2. What is the function of a photodiode?

Answer: A photodiode detects light and converts light energy into electrical current. It operates mainly in reverse bias.

3. What is the output of a NOT gate if the input is HIGH?

Answer: The output of a NOT gate is LOW when the input is HIGH.

3. Short Answer Questions.

1. Explain how a p-n junction diode acts as a rectifier.

Answer: A p-n junction diode allows current to pass in only one direction, conducting during the forward bias and blocking during reverse bias. Thus, it converts alternating current (AC) into direct current (DC) by passing current only during the positive half-cycle and blocking the negative half-cycle.

2. Describe the I-V characteristics of a Light Emitting Diode (LED).

Answer: For an LED, the current increases very slowly with voltage until it reaches the threshold. Beyond this voltage, the current rises steeply, and the LED emits visible light. In reverse bias, almost no current flows, and the LED does not emit light.

3. How does a Zener diode regulate voltage in a circuit?

Answer: In reverse bias, a Zener diode maintains a constant output voltage equal to its breakdown voltage, even if the input voltage or load current changes. This property is used for voltage regulation in electronic circuits, protecting sensitive devices from voltage fluctuations.

4. True or False Questions.

1. In a semiconductor, the resistivity increases with temperature.

Answer: False

2. The output of an OR gate is HIGH if any of its inputs is HIGH.

Answer: True

3. Fill in the Blanks Questions.

1. The energy gap in a typical silicon semiconductor is approximately ______ eV.

Answer: 1.1

2. In reverse bias, the current through an ideal diode is ______.

Answer: zero

3. A solar cell directly converts ______ energy into electrical energy.

Answer: solar (light)

Why Electronic Devices Matter for NEET Physics Preparation

Electronic Devices form a core part of NEET Physics. Understanding semiconductors, diodes, and logic gates builds a strong foundation for both MCQ-based and conceptual problems. These concepts have direct application in exams and modern electronic technology.

Most questions on this topic test logic gates, I-V characteristics, and device principles. Focusing on these areas can help you tackle questions efficiently and score better in the NEET Physics section.

At Vedantu, we make sure students get simple and relevant explanations for Electronic Devices. This helps you manage tricky concepts and gives you extra confidence for your NEET 2026 exam journey.