ICS Part 2 Physics Chapter 18 Short Questions Preparation

Question # 1

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 # 2

Define logic system and logic gates.

Ans 1: A digital system deals with the quantities or variable which have only two discrete values or state.
The electronic circuits which implements the various logic operation are known as logic gates.

Question # 3

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 # 4

Define current of gain of a transistor

Ans 1: The ratio of output current to input current is called current gain of a transistor.The ratio of collector current to base current is called current gain of a transistor.

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

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 # 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

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 # 9

What is the role of potential barrier in a diode?How it is formed in diode?

Ans 1: At the formation of pn-junction ,the free electrons in n-region because of their random motion diffuse into the p-region,.As a result of this diffusion a region is formed around the junction consisting of positive and negative ions,Due to charge on these ions a potential difference develops across the depletion region,This potential difference is called potential barrier,stops further diffusion of electron into the p-region.

Question # 10

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.

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ICS Part 2 Physics Chapter 18 Short Questions Preparation

12th Class PhysicsShort Questions Preparation

12th Class Physics Chapter Wise Preparation

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

Why charge carriers are not present in the depletion region?

Define logic system and logic gates.

Differentiate between the forward biased and the reserve biase.

Define current of gain of a transistor

What is photovoltaic cell?Discuss its working?

Give any two characteristics of operational amplifier.

Write a note on LED.

How is p-n junction formed?

What is the role of potential barrier in a diode?How it is formed in diode?

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

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

Why charge carriers are not present in the depletion region?

Define logic system and logic gates.

Differentiate between the forward biased and the reserve biase.

Define current of gain of a transistor

What is photovoltaic cell?Discuss its working?

Give any two characteristics of operational amplifier.

Write a note on LED.

How is p-n junction formed?

What is the role of potential barrier in a diode?How it is formed in diode?

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

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

Why is the photodiode operated in reverse biased state?

What is OP-GATE?

Define Open Loop gain of operational amplifier.

What is meant by rectification?

What is photovoltaic cell?Discuss its working?

Give four application or uses of photodiode?

How is the XOR gate so called?

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

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

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

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

Differentiate between the forward biased and the reserve biase.

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

What is AND Gate?

Explain why an ordinary Silicon diode does not emit light.

Why is the photodiode operated in reverse biased state?

What is photodiode?Write down its two main applications.

How the normal operation of transistor is achieved?

Give any two characteristics of operational amplifier.

Define Open Loop gain of operational amplifier.

Why the biasing requirement of the junction of a transistor for its normal operation?

ICS Part 2 Physics Chapter 18 Short Questions Preparation

12th Class Physics
Short Questions Preparation