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 32 of 33
- A. Diode
- B. Transistor
- C. Capacitor
- D. Inductor
Explanation: A diode is commonly used to convert alternating current (AC) into direct current (DC) in electronic circuits
Correct answer: Diode- A. 1
- B. 2
- C. 3
- D. 4
Explanation: In full-wave rectification, typically, 4 diodes are used. It allows for the conversion of both the positive and negative halves of the AC…
Correct answer: 4623. Transistors can be:
- A. half wave rectifier
- B. full wave rectifier
- C. both
- D. none
Explanation: Transistor can be used as a switch for opening and closing of the circuit.
Correct answer: none624. A half wave rectifier is operating from 50 Hz mains. The fundamental frequency of ripple will be _.
- A. 100 Hz
- B. 25 Hz
- C. 200 Hz
- D. 50 Hz
Explanation: The voltage that is obtained in a half wave rectifier has one variation in one cycle of AC voltage.
Correct answer: 50 Hz625. A full-wave rectifier is operating from 50Hz mains. The fundamental frequency of ripple will be?
- A. 100 Hz
- B. 25Hz
- C. 50Hz
- D. 200Hz
Explanation: Full-wave rectification is a type of rectification in which output is obtained for both halves of a.c.
Correct answer: 100 Hz- A. 1.21
- B. 0.5
- C. 0.482
- D. 0.9
Explanation: The ratio of the RMS value of an alternating current component in the rectified output to the average value of rectified output is…
Correct answer: 0.482- A. Larger the peak-to-peak value of ripple voltage
- B. Larger the peak current in the rectifying diode
- C. Longer the time that current pulse flows through the diode
- D. Smaller the voltage across the load
Explanation: The time constant for a capacitor has the value RC, where R is the load resistance and C is the shunt capacitor's capacitance.
Correct answer: Longer the time that current pulse flows through the diode- A. NOR.
- B. XNOR.
- C. XOR.
- D. Both B and C.
Explanation: In logic gates, a NAND gate produces an output of 1 unless both inputs are 1. For inputs A=0 and B=1, the NAND gate outputs 1.
Correct answer: XOR.- A. High voltage.
- B. Photon.
- C. Hole.
- D. Positron.
Explanation: A hole or an electron hole is a point in an atom, a lattice or a structure where an electron can exist but does not because it has been…
Correct answer: Hole.- A. No
- B. Very large
- C. Few milliamperes
- D. Both A and C
Explanation: a) No: This option suggests that practically no current flows in a reverse p-n junction.
Correct answer: No- A. Indium
- B. Aluminium
- C. Arsenic
- D. Both B and C
Explanation: N- type semiconductor is denoted by positive ion and free electron.Silicon Si has 4 valence electrons and Arsenic As has 5 valence…
Correct answer: Arsenic- A. -1
- B. 10
- C. -10
- D. 1
Explanation: Explanation:The gain of an inverting amplifier using an operational amplifier is given by the ratio of the feedback resistor to the input…
Correct answer: -10- A. AND Gate
- B. XNOR Gate
- C. NAND Gate
- D. NOR Gate
Explanation: Explanation:If inputs A = 1, B = 0, and output X = 1, the it corresponds to the operation of a NAND Gate.
Correct answer: NAND Gate- A. 250
- B. 100
- C. 150
- D. 200
Explanation: Explanation: Collector currect: Ic = 10mA = 10 × 10-3 A Base current = IB = 50μA = 50 × 10-6 A Current gain = β = ?As we know that, β = Ic…
Correct answer: 200- A. 0°
- B. 270°
- C. 360°
- D. 180°
Explanation: Explanation:When an operational amplifier is used as an inverting amplifier, the output terminal with a phase shifted of 180°.
Correct answer: 180°- A. 10-5 cm
- B. 10-6 m
- C. 10-6 mm
- D. 10-6 µm
Explanation: The base region in a transistor is the central area that is lightly doped compared to the emitter and collector regions.
Correct answer: 10-6 m- A. Neutral (0)
- B. Positive
- C. Negative
- D. Variable
Explanation: An N-type semiconductor is doped with pentavalent elements, which introduce additional free electrons.
Correct answer: Neutral (0)- A. Wheatstone Circuit
- B. Bridge circuit
- C. Filter circuit
- D. Ripple circuit
Explanation: The filter circuit incorporates a capacitor which charges and discharges in order to smooth the circuit.
Correct answer: Filter circuit639. The current gain of a transistor having a collector current of 10 mA and a base current of 40 A is:
- A. 2.5
- B. 25
- C. 250
- D. 2500
Explanation: Current gain is the ratio of the change in the collector current to the change in the emitter current in a transistor.
Correct answer: 250- A. Nonviolent
- B. Divalent
- C. Trivalent
- D. Pentavalent
Explanation: A p-type crystal is formed when a semiconductor crystal, such as Germanium (Ge) or Silicon (Si), is doped with an impurity that has one…
Correct answer: Trivalent