SEMICONDUCTOR PART-1

Which is the symbol of a PN junction diode?

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Main phenomenons associated with formation of p-n junctions are

• Drift only

• Diffusion only

• Diffusion and Drift

• only doping

The region on either side of the junction which becomes free from the mobile charge carriers is called

• Energy gap region

• Charge free region

• Diffusion region

• Depletion region

The main constructional difference between Half wave and Full wave rectifier

• Number of parts used in 1^st type is Half of parts used in 2^nd type

• Some kind of half wave is used in 1^st type

• use of Centre tapping in case of 1st type and not in 2nd type

• use of Centre tapping in case of 2^nd type and not in 1^st type

Examples for N-type material

• Arsenic

• Aluminium

• Antimony

• Bismuth

In PN junction forward biasing width of the depletion region

• Increases

• Decreases

The phenomenon used in LED is called

• Electro illuminance

• Electrolence

• Electro Luminance

Which image shows the output of a sine-wave after it has gone through a diode? (Half-wave rectified)

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• halfwave rectified

• fullwave rectified

• sine wave

• light bulb

The applied input a.c. power to a half-wave rectifier is 100 watts. The d.c. output power obtained is 40 watts. What is the rectification efficiency ?

• 40%

• 60%

• 80%

• 90%