Electronic Devices Practice Questions
NEET · Physics · 1561 free MCQs with instant results and detailed explanations.
1561
Total
330
Easy
720
Medium
511
Hard
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Topics in Electronic Devices
Semiconductors
314
p-n Junction
312
Transistor
307
Logic Gates
309
Diode
319
Sample Questions from Electronic Devices
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the main role of a semiconductor in electronic devices?
A.
To conduct electricity without any resistance
B.
To allow control of electrical current
C.
To store electrical energy
D.
To insulate against electrical flow
Show Answer & Explanation
Correct Answer: B
Semiconductors can control electrical current, allowing them to be used in various applications like diodes and transistors.
Q2
Easy
Which of the following materials is a commonly used semiconductor?
A.
Copper
B.
Silicon
C.
Aluminium
D.
Gold
Show Answer & Explanation
Correct Answer: B
Silicon is widely used as a semiconductor due to its suitable electrical properties and abundance.
Q3
Easy
What is the effect of temperature on the conductivity of intrinsic semiconductors?
A.
Conductivity decreases with temperature
B.
Conductivity remains constant
C.
Conductivity increases with temperature
D.
Conductivity becomes zero
Show Answer & Explanation
Correct Answer: C
In intrinsic semiconductors, as temperature increases, more electrons gain energy to jump into the conduction band, hence increasing conductivity.
Q4
Medium
In a p-n junction diode, what happens to the conductivity when it is forward biased?
A.
Conductivity increases due to the movement of charge carriers.
B.
Conductivity decreases due to recombination.
C.
Conductivity remains unchanged.
D.
Conductivity increases due to a decrease in temperature.
Show Answer & Explanation
Correct Answer: A
When a p-n junction diode is forward biased, the applied voltage reduces the barrier potential, allowing charge carriers (electrons and holes) to move freely across the junction, thus increasing conductivity.
Q5
Medium
What is the role of the depletion region in a p-n junction diode?
A.
It allows current to flow easily.
B.
It acts as an insulating barrier preventing electron movement.
C.
It increases the capacitance of the diode.
D.
It converts AC to DC.
Show Answer & Explanation
Correct Answer: B
The depletion region in a p-n junction diode is an area devoid of free charge carriers and acts as an insulating barrier, preventing current flow until a sufficient voltage is applied to overcome it.
Q6
Medium
If the temperature of a semiconductor increases, what effect does it have on its conductivity?
A.
Conductivity decreases.
B.
Conductivity remains constant.
C.
Conductivity increases.
D.
Conductivity becomes zero.
Show Answer & Explanation
Correct Answer: C
As temperature increases, more electrons gain enough energy to jump from the valence band to the conduction band, resulting in an increase in the number of charge carriers and therefore an increase in conductivity.
Q7
Medium
In which of the following configurations is a transistor used as a switch?
A.
Common emitter configuration.
B.
Common collector configuration.
C.
Common base configuration.
D.
None of the above.
Show Answer & Explanation
Correct Answer: A
A transistor used in common emitter configuration can switch between the on and off states effectively, making it ideal for switching applications due to its high gain and ability to control a larger current with a smaller input current.
Q8
Hard
In a silicon semiconductor, the intrinsic carrier concentration at room temperature is approximately 1.5 × 10^10 cm^-3. If the temperature increases to 400 K, what is the expected ratio of intrinsic carrier concentration at 400 K to that at room temperature?
A.
100
B.
1000
C.
10
D.
500
Show Answer & Explanation
Correct Answer: B
The intrinsic carrier concentration in semiconductors increases exponentially with temperature. The ratio at elevated temperatures can be estimated to be around 1000 times higher due to the exponential dependence of carrier concentration on temperature.
Q9
Hard
A p-n junction diode has a forward bias voltage of 0.7 V and a reverse bias breakdown voltage of 50 V. What is the maximum allowable reverse current if the diode can handle 10 mA in forward bias?
A.
0 mA
B.
10 mA
C.
1 mA
D.
5 mA
Show Answer & Explanation
Correct Answer: A
In reverse bias, ideally, a diode should not conduct current. Allowable reverse current is typically very close to zero in ideal conditions, while breakdown can allow more current but can damage the diode.
Q10
Hard
An n-type semiconductor has a majority carrier concentration of 2 × 10^16 cm^-3. If the intrinsic carrier concentration of silicon is 1.5 × 10^10 cm^-3, what is the minority carrier concentration?
A.
1.5 × 10^6 cm^-3
B.
1.5 × 10^10 cm^-3
C.
1.5 × 10^5 cm^-3
D.
2 × 10^10 cm^-3
Show Answer & Explanation
Correct Answer: A
The minority carrier concentration in n-type semiconductors can be found using the mass action law: np = ni², where n is the majority carrier concentration and p is the minority carrier concentration. Here, p = ni²/n.
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Electronic Devices — NEET Physics Practice Questions Online
This page contains 1561 practice MCQs for the chapter Electronic Devices in NEET Physics. The questions are organized by difficulty — 330 easy, 720 medium, 511 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 5 topics, giving you comprehensive coverage of the entire chapter.