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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- A. Reverse biased
- B. Forward biased
- C. Not biased
- D. None of these
Explanation: When the diode is forward-biased, the voltage across the diode is in the direction that allows current to flow through it, and the diode…
Correct answer: Forward biased- A. Electrons
- B. Holes
- C. Majority carriers
- D. Minority carriers
Explanation: The more abundant charge carriers are called majority carriers, which are primarily responsible for current transport in a piece of…
Correct answer: Majority carriers- A. Electrons
- B. Holes
- C. Majority carriers
- D. Minority carriers
Explanation: The less abundant charge carriers are called minority carriers; in n-type semiconductors they are holes, while in p-type semiconductors…
Correct answer: Minority carriers- A. Anode
- B. Cathode
- C. Neutral
- D. None of these
Explanation: The diode is a device formed from a junction of n-type and p-type semiconductor material.
Correct answer: Anode- A. The negative halfcycle of input AC
- B. The positive half cycle of input AC
- C. Both the input of AC
- D. None of the above
Explanation: The half-wave rectifier is a rectifier that allows one-half of the AC voltage signal and blocks the other half, and converts AC voltage to…
Correct answer: The positive half cycle of input AC- A. The positive half cycle of input AC
- B. The negative half cycle of input AC
- C. Complete cycle of input AC
- D. None of these
Explanation: The input AC supplied to the full wave rectifier is very high. The step-down transformer in the rectifier circuit converts the high…
Correct answer: The negative half cycle of input AC- A. Few ohms
- B. Mega ohms
- C. Infinity
- D. Kilo ohms
Explanation: ⇒ Forward bias is a potential used to reduce the resistance of a PN junction.⇒ A forward biased PN junction has a minimum depletion layer…
Correct answer: Few ohms- A. Low
- B. Zero
- C. Very high
- D. None of these
Explanation: ⇒ Reverse bias is a potential used to increase the resistance of a PN junction A reverse-biased PN junction has a maximum depletion layer…
Correct answer: Very high- A. Modulation
- B. Amplification
- C. Oscillation
- D. Rectification
Explanation: CONCEPT:Rectification: A rectifier is a device that converts alternating current (AC) into a direct current (DC).
Correct answer: Rectification- A. Depletion region
- B. Potential difference
- C. Curved region
- D. None of above
Explanation: When the p-type and the n-type materials are kept in contact with each other, the junction between them behaves differently from either…
Correct answer: Depletion region- A. 0.6 volt
- B. 0.9 volt
- C. 0.7 volt
- D. 0.2 volt
Explanation: Typically at room temperature the voltage across the depletion layer for silicon is about 0.7 volts
Correct answer: 0.7 volt- A. 0.3 volt
- B. 0.7 volt
- C. 0.6 volt
- D. 0.8 volt
Explanation: Typically at room temperature the voltage across the depletion region for germanium is about 0.3 - 0.35 volts
Correct answer: 0.3 volt- A. Light emitting diode
- B. Photo diode
- C. Photo voltaic cell
- D. All of above
Explanation: Special Purpose P-N Junction Diodes includes:Zener DiodeLight-Emitting DiodePhotodiodeA solar cell or photovoltaic devicesLight-emitting…
Correct answer: All of above- A. Genninium
- B. Silicon
- C. Gallium arsenide
- D. Phosphorus
Explanation: LEDs are comprised of compound semiconductor materials, which are made up of elements from group III and group V of the periodic table…
Correct answer: Gallium arsenide- A. Seven
- B. Five
- C. Six
- D. Eight
Explanation: Light Emitting Diode (LED) is the most widely used semiconductor which emits either visible light or invisible infrared light when forward…
Correct answer: Seven- A. For detection of visible light
- B. For detection of invisible light
- C. Both (a) and (b)
- D. As an inductor
Explanation: Photodiodes are a class of diodes that converts light energy to electricity.
Correct answer: Both (a) and (b)- A. Photodiode
- B. Photo voltaic cell
- C. Light emitting
- D. All of above
Explanation: A photodiode is a semiconductor device that is used to detect light. In order to detect light, a photodiode is exposed to a photon of…
Correct answer: Photodiode- A. Photo voltaic cell
- B. Light emitting diode
- C. Photodiode
- D. None of these
Explanation: There are two relevant mechanisms:First, the intended one: Minority carriers, generated by light within or close to the p-n junction and…
Correct answer: Photodiode- A. In the reversed biased situation
- B. In the forward biased situation
- C. With the light incident upon
- D. Both (a) and (c)
Explanation: The photodiodes are used in reverse bias condition because the change in reverse current through the photodiode due to change in light…
Correct answer: Both (a) and (c)- A. Solar cell
- B. Generator
- C. Thermo couple
- D. Thermister
Explanation: A solar cell or photovoltaic cell is an electronic device that converts the energy of light directly into electricity by means of the…
Correct answer: Solar cell