Free Electronics MCQs with Answers
660 Electronics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
A p-n junction forms when p-type and n-type semiconductor regions meet, creating a depletion layer, barrier potential and rectifying action. The work covers forward and reverse bias, junction current, diode characteristics, and how a diode converts alternating current into pulsating direct current through half-wave and full-wave rectification.
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Read the Electronics notesFree MDCAT chapter notes with key terms660 questions · page 31 of 33
- A. Amount of current
- B. Velocity of the light
- C. Amplitude of the light
- D. Material of semiconductor
Explanation: The color of light emitted by a light-emitting diode (LED) is determined by the material of the semiconductor used.
Correct answer: Material of semiconductor- A. Option A: X is the N-region, Y is the P-region.
- B. Option B: X is the P-region, Y is the N-region.
- C. Option C: X is the cathode, Y is the anode.
- D. Option D: X is the N-region, Y is the P-region.
Explanation: The correct answer is Option D: X is the N-region, Y is the P-region. In a PN junction, electrons naturally move from the N-region, which…
Correct answer: Option D: X is the N-region, Y is the P-region.- A. x = 0, y = 0
- B. x = 0, y = 1
- C. x = 1, y = 0
- D. x = 1, y = 1
Explanation: The correct answer is Option A:x = 0, y = 0. This is because, in the given truth table, the condition or operation being evaluated results…
Correct answer: x = 0, y = 0- A. Rectifier
- B. Photocell
- C. Photodiode
- D. Light Emitting Diode (LED)
Explanation: The correct answer is Photodiode. Photodiodes are designed to operate under reverse bias, which enhances their sensitivity to light by…
Correct answer: Photodiode- A. Diode.
- B. Buffer.
- C. Resistor.
- D. Resistor-transistor.
Explanation: The correct answer is a diode. Diodes are semiconductor devices that allow current to flow in one direction only, acting as a one-way…
Correct answer: Diode.- A. Holes.
- B. Protons.
- C. Positrons.
- D. Electrons.
Explanation: In an n-type semiconductor, the material is doped with donor atoms that have more valence electrons than the semiconductor material…
Correct answer: Electrons.- A. Voltage decreases.
- B. Voltage becomes zero.
- C. Diode resistance decreases.
- D. Diode's efficiency increases.
Explanation: In a reverse-biased junction, when the reverse current reaches its maximum value, it indicates that the diode has entered the breakdown…
Correct answer: Voltage decreases.- A. Zero.
- B. Widened.
- C. Narrowed.
- D. Unchanged.
Explanation: When a p-n junction is reverse biased, the electric field across the junction increases, causing the depletion region to widen.
Correct answer: Widened.- A. Ions.
- B. Holes.
- C. Electrons.
- D. Molecules.
Explanation: In an NPN transistor, the base is made of p-type material, where holes are the majority carriers.
Correct answer: Electrons.- A. 1
- B. 2
- C. 3
- D. 4
Explanation: For full wave rectification, the minimum number of diodes required is two (This is for a center-tapped full wave rectifier…
Correct answer: 2- A. Only positive half of input cycle
- B. Only negative half of input cycle
- C. Both halves of input cycle
- D. Any one half of input cycle
Explanation: In a half-wave rectifier, the diode conducts during the only positive half of the input cycle.
Correct answer: Only positive half of input cycle- A. -1
- B. 0
- C. +1
- D. infinite
Explanation: In a non-inverting operational amplifier, the gain is given by 1 + (R2/R1).
Correct answer: +1- A. A
- B. B
- C. C
- D. D
Explanation: The NAND gate produces an output of 0 only when all its inputs are 1. Otherwise, it outputs 1.
Correct answer: B- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The correct answer is Option B. A NAND gate produces an output that is false only when all its inputs are true; otherwise, the output is…
Correct answer: Option B- A. 4
- B. 16
- C. 32
- D. 64
Explanation: This can be calculated using the formula 2n, where n is the number of possible inputs. The number of inputs is 4.
Correct answer: 16- A. Momentum
- B. Charge
- C. Mass
- D. All of these options are correct
Explanation: Solar cell devices are known to follow the 'photovoltaic effect', which is the conversion of sunlight to direct current.
Correct answer: Charge- A. Amplifier
- B. Rectifier
- C. Diode
- D. Transistor
Explanation: The device that is used to convert AC to DC is a rectifier. A rectifier corrects or straightens the direction of the current.
Correct answer: Rectifier- A. Rectification
- B. Amplification
- C. Rectifier
- D. Conversion
Explanation: The process of converting AC to DC is called rectification. The device used for rectification is called the rectifier.
Correct answer: Rectification- A. Rectifier
- B. Transistor
- C. Capacitor
- D. Inductor
Explanation: Rectifier is a device that is used to convert AC voltage into DC voltage and is called a rectifier.
Correct answer: Rectifier- A. Amplification
- B. Rectification
- C. Magnification
- D. Resolution
Explanation: A rectifier converts alternating current to direct current and this process of converting AC to DC is known as rectification.
Correct answer: Rectification