MCQs on Analog Electronics

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01․ Which of the following is a semiconductors material ?
All the above

Semiconductors materials are silicon (Si) and germanium (Ge).Gallium arsenide (GaAs) is a compound semiconductor as it is produced from group three element gallium (31) and group five element arsenic (33) by special fabrication technique. They have electrical properties lies in between conductor and an insulator.

02․ A LED produces light when
forward biased.
reverse biased.
none of the above.

A LED is a semiconductor device which emits light when it is forward biased. The difference between the valance and conduction band produces the light energy when forward biased. The colour and the frequency of the light depends upon the material of the semiconductor.

03․ A Schottky diode is a
majority carrier device.
minority carrier device.
fast recovery diode.
both a majority and a minority carrier diode.

Schottky diode is formed by joining a semiconductor region (usually N-type) with a metal such as gold, silver or platinum. So it is a metal to semiconductor junction having only the majority carriers. It is also used for high frequency switching application above 20 GHz.

04․ When a junction diode is Reverse Biased then diode acts like .......................
Short switch
Close switch
An open switch
None of the above

When a junction diode is Reverse Biased the thickness of the depletion region increases and the diode acts like an open circuit or open switch, blocking any current flow.

05․ What is the charge of mobile charge carriers of holes ?
Negatively charged
No charged
Positively charged
None of the above

The holes are positively charged while the electrons are negatively charged. Deficiency of one electron is considered as hole or positive charge.

06․ When a junction diode is Forward Biased the thickness of the depletion region is................
Not determine

Forward voltage pushes more free electrons into the P-region and holes into N-region. This makes the depletion region smaller and starts conducting current.

07․ Which are the mobile charge carriers present in semiconductor diode ?
Both A & B

Semiconductors contain two types of mobile charge carriers, Holes and Electrons. In N type electrons as majority carrier and in P type holes as majority carrier.

08․ Diode is also called as:

Rectifier that converts alternating current which periodically reverses direction, to direct current. The process is known as rectification. Diode works only positive half of the input signal but doesn't works on the negative half cycle. So a single diode works as a half wave wave rectifier.

09․ When P-type substance is connected with negative and n-type is connected with positive terminal of the battery then P-n junction diode is in ....................
Reverse biased
Forward biased
No biased
None of the above

When a positive voltage is applied to the N-type material and a negative voltage is applied to the P-type material, then a diode is connected in a reverse bias condition. In reserve bias the holes and electrons are attracted to the battery terminal and depletion region increased.

10․ What is the majority carriers in "N" type material ?
None of the above

In N-type semiconductor, the conduction is primarily due to electrons and hence electrons are majority carriers.