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 28 of 33
- A. Electrons
- B. Holes
- C. Positrons
- D. Negative ions
Explanation: In P-type semiconductors, the majority carriers are positively charged "holes." When trivalent impurities, such as boron or gallium, are…
Correct answer: Holes- A. Protons
- B. Holes
- C. Electrons
- D. Positive ions
Explanation: In N-type semiconductors, the majority carriers are negatively charged electrons.
Correct answer: Electrons- A. A positive ion
- B. A deutron
- C. A hole
- D. An electron
Explanation: The vacant electron site left when a bond is broken is referred to as a "hole." When a covalent bond breaks, it results in the absence of…
Correct answer: A hole- A. A neutral particle
- B. A positive charge
- C. A negative charge
- D. An electron
Explanation: In semiconductor physics, a "hole" is considered the absence of an electron in a covalent bond within the crystal lattice of a…
Correct answer: A positive charge- A. High resistance
- B. Infinite resistance
- C. Low resistance
- D. None of these
Explanation: When a semiconductor diode is forward biased, it offers low resistance to the flow of electric current.
Correct answer: Low resistance- A. Reverse biased
- B. Forward biased
- C. Neither reverse nor forward biased
- D. All of these
Explanation: A PN junction conducts current only when it's forward biased. When a PN junction is forward biased, meaning the positive terminal of the…
Correct answer: Forward biased- A. The complete cycle of input A.C
- B. The negative half cycle of input AC only
- C. The positive half cycle of input AC only
- D. None of these
Explanation: In full-wave rectification, the output DC voltage is obtained across the load for the entire duration of the input AC waveform.Unlike…
Correct answer: The complete cycle of input A.C- A. Solar cells
- B. Light emitting diodes
- C. Photo diodes
- D. None of these
Explanation: A photodiode is a semiconductor device that generates a flow of current in response to incident light or photons.
Correct answer: Photo diodes549. The specially designed semiconductor diodes used as indicator lamps in electronic circuits are:
- A. Light emitting diodes
- B. Photo diodes
- C. Solar cells
- D. hoto voltaic cells
Explanation: The Explanation for this question will be added soon!
Correct answer: Solar cells- A. The emitter-base junction is forward biased and the collector-base junction is reverse biased
- B. The emitter-base junction is reverse biased and the collector-base junction is forward biased
- C. Both the junctions are reverse biased
- D. Both the junctions are forward biased
Explanation: The correct option is:The emitter-base junction is forward biased, and the collector-base junction is reverse biased.In a common…
Correct answer: The emitter-base junction is forward biased and the collector-base junction is reverse biased- A. A voltage amplifier
- B. A current amplifier
- C. An oscillator
- D. All of the above
Explanation: The Explanation for this question will be added soon!
Correct answer: A voltage amplifier- A. Semi conductors
- B. Insulators
- C. Conductors
- D. Wood
Explanation: Solar cells are primarily composed of semiconductor materials.They consist of a thin sandwich or layering of semiconductor materials…
Correct answer: Semi conductors- A. Carbon
- B. Iron
- C. Silicon
- D. Mercury
Explanation: The material primarily used in fabricating solar cells is silicon.Silicon is the most widely used semiconductor material in the production…
Correct answer: Iron- A. Gallium
- B. Indium
- C. Boron
- D. Arsenic
Explanation: Indium is not an acceptor impurity.Among the options listed, gallium, boron, and arsenic are examples of impurities that act as acceptors…
Correct answer: Indium- A. Greater than that of infra-red rays
- B. Smaller than that of infra-red rays
- C. Smaller than that of ultraviolet rays
- D. None of these
Explanation: Radio waves used for transmission have wavelengths greater than infrared (IR) waves and shorter wavelengths than microwaves.
Correct answer: Greater than that of infra-red rays- A. Y -rays
- B. X-rays
- C. Ultraviolet rays
- D. Infra-red rays
Explanation: Among the options provided:- Gamma rays have smaller wavelengths compared to infrared (IR), ultraviolet (UV), and X-rays.In the…
Correct answer: Y -rays- A. Parallel to the electric field
- B. Perpendicular to the electric field
- C. At an angle of 60o with the electric field
- D. None of these
Explanation: In an electromagnetic wave, the direction of the magnetic field is perpendicular to the direction of the electric field and both are…
Correct answer: Perpendicular to the electric field- A. Constant
- B. Changing
- C. Zero
- D. None of these
Explanation: The Explanation for this question will be added soon!
Correct answer: Zero- A. Semi conductors only
- B. Conductors only
- C. Insulators only
- D. All of these
Explanation: The band theory of solids successfully classifies solids into three main categories based on their electrical conductivity:1.
Correct answer: All of these- A. High doping
- B. Low doping
- C. Zero doping
- D. None of these
Explanation: The base of a transistor is typically lightly doped compared to the emitter and collector regions.For an NPN transistor:- The emitter is…
Correct answer: Low doping