Electronics MCQ's (Multiple choice questions)

"In this series, all parts of electronics will be covered, including basic electronics, analog electronics, power electronics, and digital electronics."

 

1. The diode used for voltage regulator is ?

A) Zener diode
B) schottky diode
C) varactor diode
D) tunnel diode

ANSWER= (A) Zener diode
Explaination:- In the breakdown region it can be used as voltage regulator it work as reverse biased.
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2. Transistor work as an amplifire in which region?

A) depletion region
B) active region
C) saturation region
D) cut-off region

ANSWER= (A) active region
Explaination:- ACTIVE REGION ( FOR AMPLIFICATION THE TRANSISTOR MUST BE IN ACTIVE REGION IN ACTIVE REGION EMITTER BASE JUNCTION IS FORWARD BIASED AND COLLECTOR BASE JUNCTION IS REVERSED BIASED.)
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3. Which of the following is current controlled device?

A) MOSFET
B) BJT
C) IGBT
D) FET

ANSWER= (B) BJT
Explaination:- Voltage controlled device = IGBT,FET,MOSFET Current controlled device = BJT
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4.which device is used to increase the magnitude of the signal?

A) rectifire
B) attenuator
C) amplifire
D) invertor

ANSWER= (A) amplifire
Explaination:- Amplifire is used to increase the magnitude of the signal basically it increase the streangth of weak signals and attenuator is a device that reduce the magnitude of electrical signal.attenuatpr is just opposite of amplifire. Rectifire convert AC to DC signal and invertor convert DC to AC signal.
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5.Avalanche breakdown is caused due to?

A) emission of electron
B) due to ionization
C) high temprature
D) all of the above

ANSWER= (B) due to ionization
Explaination:- Avalanche breakdown accures when a high reverse voltage is applied across the diode.as we increase the reverse voltage electric field across the junction is increase and cause electric breakdown in a diode.
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6.which of the following material has negtive temprature cofficient?

A) elctrolyte
B) silver
C) copper
D) none of the above

ANSWER= (A) elctrolyte
Explaination:- electolyte has negtive temprature cofficiant of resistance.
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7.An scr consist of____PN junction.

A) 3
B) 5
C) 4
D) 2

ANSWER= (A) 3
Explaination:- scr consist of three PN junction and four layer device.
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8.What type of semiconductor is used in LED electronic circuits?

A) compound semiconductor
B) degenerated semiconductor
C) compensated semiconductor
D) none of the above

ANSWER= (A) compound semiconductors
Explaination:- compound semiconductors are used in LED because they have direct band gap.in direct photon are easily generated.
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9.A semiconductor has generally____valence electron?

A) 2
B) 4
C) 5
D) 6

ANSWER= (B) 4
Explaination:- 4 velence electron.
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10.A bond formed by semiconductor is ?

A) ionic
B) covalent
C) metalic
D) none of the above

ANSWER= (B) covalent
Explaination:- A semiconductor is formed by "COVLENT BOND".
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11.The number of valence electrons of P and Si are___ respectively?

A) 3 and 4
B) 5 and 4
C) 4 and 4
D) 4 and 5

ANSWER= (B) 5 and 4
Explaination:- A valence electron is an outer shell electron that is associated with an atoms since the electrons are in third shell so Si has 4 velence electron and phosphorus have 5 velence electron.
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12.the germanium crystal behaves as an insulator at ?

A) 0 degree k
B) 273 degree k
C) 100 degree k
D) 10 degree k

ANSWER= (A) 0 degree k
Explaination:- Silicon and germanium are semiconductors they both become insulator at absolute zero temprature.
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13.which of the following is The donor type impurties

A) Aluminium
B) phosphorous
C) boron
D) iron

ANSWER= (B) phosphorous
Explaination:- arsenic,antimony,bismuth,and phosphorous are pentavalent impurities because these material donate electron.
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14.When an electron is removed from an atom it becomes ?

A) covalent
B) positron
C) ionised
D) molecule

ANSWER= (C) ionised

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15.which of the foliowing is a trivalent element?

A) boron
B) indium
C) aluminium
D) all of the above

ANSWER= (D) all of the above
Explaination:- trivalent means atom have 3 balance electrons.
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16.which of the following are immobile ?

A) holes
B) electron
C) ions
D) none of the above

ANSWER= (A) ions
Explaination:-mobile charge can move and immobile charge can't move in semiconductors. holes and electrons are movable and ions are not movable.
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17.Imperfaction in crystal structure result in?

A) increase conductivity
B) decrease conductivity
C) decrease mobility
D) increase mobility

ANSWER= (A) decrease mobility
Explaination:- Imperfaction in crystal structure result in decrease the mobility in semiconductor.
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18.The value of temprature cofficient of resistance of a given conductor is

A) different at different temprature
B) same at different temprature
C) remain constant always
D) none of the above

ANSWER= (A) different at different temprature
Explaination:-temprature cofficient of resistance depend upon nature of material and temprature.
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19.IN a pure semiconductor electric current is due to ?

A) both electron and holes
B) electrons alone
C) holes alone
D) none of the above

ANSWER= (A) both electron and holes
Explaination:-current which flow in a semiconductor is due to electrons as well as holes both.
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20.temprature cofficient of resistance in a pure semiconductor is ?

A) zero
B) postive
C) negtive
D) none

ANSWER= (C) negtive
Explaination:- when the temprature of semiconductting material increases the resistance of that particular material decrease hence semiconductor have negtive temprature cofficient of resistance.
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