Question # 1

How does the motion of an electron in n type substance differ from the motion of holes in a p type substance?

Ans 1: more mobile and rapid than holes in p-type substance because electrons do not require holes for their motions but p-type substance because electrons do not require holes for their motion but hole depend upon electrons for their motion,Both move in opposite direction.

Question # 2

What do LED and LASER stand for?

Ans 1: LED stands for light emitting diode..
Laser stands for light amplification stimulated emission radiation .

Question # 3

How is p-n junction formed?

Ans 1: A p-n junction is formed when a crystal of germanium or silicon is grown in such a way that is its one half is doped with a trivalent impurity and the other half with a pentavalent impurity.

Question # 4

What is the net charge on a n-type or p-type substance?

Ans 1: Since they are electrically neutral substance,So the net charge on them is zero.

Question # 5

What is photovoltaic cell?Discuss its working?

Ans 1: It consists of a thick n type region covered by a thin p-layer type.When exposed to light,it absorbs photon which generated electron-hole pairs.The electric field at the junction moves electron and holes and a current flow through the external circuit.And this current is directly proportional to the intensity of light.

Question # 6

Why charge carriers are not present in the depletion region?

Ans 1: This is due to the fact when an electron from an n region diffuses into the p-region,it leaves behind a positive ion.When this electron recombines with the hole in the p-region,a negative ion is formed,So no charge carrier are available in this region,though it contains immobile positive and negative ions.

Question # 7

Write a note on LED.

Ans 1: Light emitting diode are made from the special semiconductor such as gallium arsenide and gallium arsenide phosphide in which the potential barrier between p and n side is such that when electrons combines with a hole during forward biased conduction,a photon of visible light is emitted.
LED are used in 7-segment display,small light sources etc.

Question # 8

Give any two characteristics of operational amplifier.

Ans 1: Input Resistance: It is the resistance between the + and - input of the amplifier,Whose value is of the order of several mega ohms.
Output resistance:It is the resistance between the output terminal and ground.Its value is only a few ohms.

Question # 9

Differentiate between the forward biased and the reserve biase.

Ans 1: When p side is positive and n-side is negative,the diode is forward biased.The width of depletion region reduces to which more current is allowed to flow across the junction.The forward resistance is few ohms.
Ans 2: When p side is negative and n side is positive,the diode is reserved biased.The width of depletion region is increased and a very small current flows across the junction due to flow of minority charges carriers,The resistance offered by the diode is several mega ohms.

Question # 10

Give four application or uses of photodiode?

Ans 1: It is used as
1. Detection of both visible and invisible radiations.
2. Logic circuits
3. Automatic switching
4. Optical communication equipment

Latest Educational News Stories

Pakistan's Largest Database of Colleges and Universities

BS Programs

University Past Papers

University Results

Exam Results 2024

Study Abroad Programs and Opportunities for Pakistani Students

Online Short Questions Preparations

Online Short Questions For Chapter 7 "ICS Part 2 Physics Chapter 18 Short Questions Preparation "

Physics - ICS Part 2 Physics Chapter 18 Short Questions Preparation

How does the motion of an electron in n type substance differ from the motion of holes in a p type substance?

What do LED and LASER stand for?

How is p-n junction formed?

What is the net charge on a n-type or p-type substance?

What is photovoltaic cell?Discuss its working?

Why charge carriers are not present in the depletion region?

Write a note on LED.

Give any two characteristics of operational amplifier.

Differentiate between the forward biased and the reserve biase.

Give four application or uses of photodiode?

Prepare Complete Set Wise Questions For Chapter 7 "ICS Part 2 Physics Chapter 18 Short Questions Preparation "

Set 1

Set 2

Set 3

ICS Part 2 Physics Chapter 18 Short Questions Preparation - Set 1

How does the motion of an electron in n type substance differ from the motion of holes in a p type substance?

What do LED and LASER stand for?

How is p-n junction formed?

What is the net charge on a n-type or p-type substance?

What is photovoltaic cell?Discuss its working?

Why charge carriers are not present in the depletion region?

Write a note on LED.

Give any two characteristics of operational amplifier.

Differentiate between the forward biased and the reserve biase.

Give four application or uses of photodiode?

ICS Part 2 Physics Chapter 18 Short Questions Preparation - Set 2

What is the effect of forward biased and reverse biasing of a diode on the width of depletion region?

What is principle of vital ground?

What is semiconductor diode?

Define logic system and logic gates.

Why charge carriers are not present in the depletion region?

What is photodiode?Write down its two main applications.

Give any two characteristics of operational amplifier.

How the current flows in forward and reverse biased diode?

Define Depletion region?

What is the potential barrier?What is the value of potential barrier of SI and Ge?

ICS Part 2 Physics Chapter 18 Short Questions Preparation - Set 3

Give any two characteristics of operational amplifier.

What is photovoltaic cell?Discuss its working?

What is the potential barrier?What is the value of potential barrier of SI and Ge?

Why is the photodiode operated in reverse biased state?

Give four application or uses of photodiode?

How the normal operation of transistor is achieved?

Explain why an ordinary Silicon diode does not emit light.

What is principle of vital ground?

The anode of a diode is 0.2V positive with respect to the cathode,It it forward biased?

Define logic system and logic gates.