Free Electronics MCQs with Answers
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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 21 of 33
- A. A p-type semiconductor
- B. An n-type semiconductor
- C. A p-n junction
- D. An intrinsic semiconductor
Explanation: The correct answer is a p-n junction. A p-n junction diode allows current to flow freely when forward biased (positive to p-type and…
Correct answer: A p-n junction- A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion
- B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion
- C. If Assertion is a true statement but Reason is false
- D. If both Assertion and Reason are false statements
Explanation: The assertion is true: In n-type semiconductors, electrons are the majority charge carriers and holes are the minority charge carriers.
Correct answer: If both Assertion & Reason are true but the reason is not the correct explanation of the assertion- A. It is used as a Half wave rectifier
- B. It is used as a shunt regulator
- C. It is used as an AC voltage stabilizer
- D. Both B and C
Explanation: The correct answer is Option A: 'It is used as a Half wave rectifier'. Zener diodes are primarily used for voltage regulation and…
Correct answer: It is used as a Half wave rectifier- A. 16.36
- B. 28
- C. 78
- D. 108
Explanation: To find the voltage gain (AV) of a triode, use the formula: AV = μ * gm * RL, where μ is the amplification factor, gm is the…
Correct answer: 16.36- A. Oscillator
- B. Rectifier
- C. Filters
- D. Amplifier
Explanation: In full wave rectification the Output voltage is pulsating. To make the voltage smooth a circuit known as filter can be used.
Correct answer: Filters- A. Increases under forward bias
- B. Increases under reverse bias
- C. Is independent of applied voltage
- D. All of these
Explanation: When the diode is forward biased, the width of depletion region decreases and when it is reverses biased then the width of depletion…
Correct answer: Increases under reverse bias407. The single Germanium or Silicon crystal formed after adding the pentavalent impurity is known as:
- A. Semi-conductor
- B. N- type substance
- C. p-n substance
- D. P-type substance
Explanation: When a silicon or Germanium crystal is doped with a pentavalent element, four valence electrons of the impurity atom form covalent bonds…
Correct answer: N- type substance- A. Minority carriers
- B. Holes
- C. Majority carriers
- D. Electrons
Explanation: In a forward-biased semiconductor diode, the depletion region narrows, allowing the majority charge carriers to move across the P-N…
Correct answer: Majority carriers- A. Drift of charges
- B. Diffusion of charges
- C. Both drift and diffusion of charges
- D. Depends on the nature of the material
Explanation: In a forward-biased P-N junction diode, the applied voltage reduces the barrier potential, allowing majority carriers to move across the…
Correct answer: Diffusion of charges- A. Increases slowly and then remains fixed
- B. Suddenly increases and then remains fixed
- C. Remains fixed
- D. Decreases slowly
Explanation: As the reverse voltage is increased from "0", the reverse current quickly rises to its saturation value "10", As the reverse current…
Correct answer: Remains fixed- A. Diffusion of carriers
- B. Drift of electrons
- C. Drift of holes
- D. Migration of impurity ions
Explanation: Just after the formation of junction. The free electrons from the n-region diffused into the p-region and holes from p-region diffused…
Correct answer: Diffusion of carriers- A. C
- B. A
- C. C,B,D
- D. A,B,C,D
Explanation: Considering the typical behavior of a full wave rectifier, option 3 (CBD) is the most likely correct answer.
Correct answer: C,B,D- A. A
- B. B
- C. C
- D. D
Explanation: To make the smooth a circuit known as filtering,capacitor can be used in which basically capacitor is connected in parallel with the load.
Correct answer: D- A. As rectifier
- B. For getting light radiation
- C. As amplifier
- D. For converting AC to DC
Explanation: P-N junction diodes can be used as rectifiers, in photodiodes and LED
Correct answer: As amplifier- A. A
- B. B
- C. C
- D. D
Explanation: The diode will conduct for every ripple (pulse). So, the output will be same as that of input.
Correct answer: D- A. 0.1 A
- B. 0.093 A
- C. 10.75 A
- D. Zero
Explanation: The circuit consists of a 100Ω resistor and a silicon diode in series with a 10V battery.
Correct answer: 0.093 A- A. 30 Hz
- B. 60 Hz
- C. 120 Hz
- D. 60/2π Hz
Explanation: A full wave rectifier converts the entire AC waveform to a pulsating DC, effectively doubling the frequency of the input signal.
Correct answer: 120 Hz- A. 35V and 35V
- B. 35V and 70V
- C. 50V and 70V
- D. 70V and 140V
Explanation: The RMS value for a half-wave rectifier is calculated as Vrms = Vpeak/2.
Correct answer: 50V and 70V419. What is the current flowing in R2 in the circuit shown in Fig.? Given: R1 = 500Ω and R2 = 1kΩ .
- A. 0mA
- B. 5mA
- C. 10mA
- D. 15mA
Explanation: In a parallel circuit, the voltage across all components is the same. Given that the voltage across R2 is 5V, we apply Ohm's Law (V=IR) to…
Correct answer: 5mA- A. 50Hz
- B. 100Hz
- C. 200Hz
- D. 25Hz
Explanation: The input signal is given as 250sin100πt. The angular frequency (ω) here is 100π, which corresponds to a frequency (f) of 50Hz (since ω =…
Correct answer: 100Hz