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 18 of 33
- A. Magnetic Resonance Imaging
- B. Ultrasonography
- C. Computerized Axial Topography
- D. Positron Emission Tomography
Explanation: Computed tomography (CT) scanning, also known as, especially in the older literature and textbooks, computerized axial tomography (CAT)…
Correct answer: Computerized Axial Topography- A. A
- B. B
- C. C
- D. D
Explanation: The most typical outcome of an X- ray tube is shown in C, which is a factual recall from the book.
Correct answer: C- A. γ-rays
- B. X-rays
- C. Infra-red radiations
- D. Ultra-violet radiations
Explanation: Gamma rays have the highest energy in all of the above mentioned, it is because of their highest frequency among all, as shown below:
Correct answer: γ-rays- A. 2 x 10^-19 J
- B. 1.6 x 10^-19 J
- C. 3.2 x 10^19 J
- D. 3.2 x 10^-16 J
Explanation: The formula relating energy, charges, and voltages is:APE = qAV. PE=(2x10^3)*(1.6x10^-19)PE=3.2x10^-16 J.As it is a numerical, it can have…
Correct answer: 3.2 x 10^-16 J- A. Photography
- B. 3-D cinema
- C. Holography
- D. Tomography
Explanation: Holography is a process that creates three-dimensional images called holograms using laser beams, the properties of intensity interference…
Correct answer: Holography- A. A
- B. B
- C. C
- D. D
Explanation: The outputs of each NAND gate is given by AB and AB, making them the 2 inputs for the OR gate, so the final output X would be AB+AB.
Correct answer: D- A. Voltage is connected to 'Y' input and time base is switched on
- B. Voltage is connected to 'X' input and time base is switched off
- C. Voltage is connected to 'Y' input and time base is switched off
- D. Voltage is connected to 'X' input and time base is switched on
Explanation: If an AC voltage is applied across the Y-plates when the timebase is on then the sinusoidally varying voltage makes the spot move up and…
Correct answer: Voltage is connected to 'Y' input and time base is switched on- A. Amplification, phase shift of 180˚
- B. Amplification, phase shift of 60˚
- C. Amplification, no phase shift
- D. None of the given options
Explanation: An amplifier's non-inverting input refers to the pin configuration. The non-inverting input is the terminal marked with a plus (+) sign…
Correct answer: Amplification, no phase shift- A. There are two wires (called leads) attached to an LED
- B. While connecting to a circuit, the longer lead of LED is always connected to the positive terminal of the battery
- C. While connecting to a circuit, the shorter lead of LED is always connected to the positive terminal of the battery
- D. LED can be used to detect weak current
Explanation: While connecting to a circuit, the shorter lead of the LED is always connected to the positive terminal of the battery.
Correct answer: While connecting to a circuit, the shorter lead of LED is always connected to the positive terminal of the battery350. In the case of germanium, the value of potential barrier develops across the depletion region is
- A. 0v
- B. 0.3V
- C. 0.7V
- D. 0.9V
Explanation: 0.3 V for Germanium and 0.7 V for silicon.
Correct answer: 0.3V- A. Avalanche effect
- B. Zener effect
- C. Early effect
- D. High-field emission
Explanation: In reverse bias, if voltage is increased, due to available energy, a covalent bond breaks, and a large number of electrons are released.
Correct answer: Zener effect- A. IC + IB
- B. IC - IB
- C. IC x IB
- D. Zero
Explanation: NPN transistors let the current flow from the emitter to the collector and base controls the flow of current through it.
Correct answer: IC + IB- A. One
- B. Two
- C. Three
- D. Four
Explanation: Only 3 modulations are possible. Amplitude Modulation, Frequency Modulation and Phase Modulation.
Correct answer: Three- A. Half wave
- B. Full wave
- C. Bridge
- D. Both half and full wave
Explanation: Bridge rectifier is formed by connecting four diodes in the form of a Wheatstone bridge.
Correct answer: Bridge- A. Lower half cycle
- B. Upper half cycle
- C. Both lower and upper half cycles
- D. One quarter cycle
Explanation: c) Both lower and upper half cycles: This option is correct. A full-wave rectifier passes both the lower (negative) and upper (positive)…
Correct answer: Both lower and upper half cycles- A. inverting and triple
- B. inverting and double
- C. non-inverting and triple
- D. non-inverting and double
Explanation: In an inverting configuration, the input signal is applied to the inverting input terminal (-) of the operational amplifier.
Correct answer: inverting and double- A. IC + IB
- B. IC - IB
- C. IC x IB
- D. Zero
Explanation: Emitting current=Collecting current+Base current.
Correct answer: IC + IB- A. Half wave rectifier
- B. Gate
- C. Night switch
- D. Full wave rectifier
Explanation: C is the answer as the polarity of the output of the OP-AMP would change based on the input and since the LDR is placed on one of the…
Correct answer: Night switch- A. Holes
- B. electrons
- C. neutrons
- D. protons
Explanation: In a p-type semiconductor, holes are the majority charge carriers and electrons are minority charge carriers.
Correct answer: Holes- A. increases
- B. decreases
- C. remains same
- D. none of them
Explanation: When the surrounding temperature rises, it causes significant increase in minority carrier creation and as a result it causes a…
Correct answer: increases