ICS Part 2 Physics Chapter 18 Short Questions Preparation

12th Class Physics
Short Questions Preparation

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

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Physics - ICS Part 2 Physics Chapter 18 Short Questions Preparation

Question # 1

What is semiconductor diode?

Ans 1: p-n junction is called semiconductor diode.

Question # 2

How the current flows in forward and reverse biased diode?

Ans 1: In forward biasing,the external potential difference supplies energy to free electrons in n-region and holes in p-region to overcome the potential barrier,a current of the orderof a few milli-amperes begins to flow across the pn junction.
In reverse biasing ,no current flow due to the majority charge carrier,However a very small current of the order of of few micro amperes flow across the junction due to minority charge carriers.It is also known as reverse current or leakage current.

Question # 3

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 # 4

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 # 5

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 # 6

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

Ans 1: Yes when anode is 0.2V positive with respect to cathode,it is forward biased.But the value of potential barrier for germanium is 0.3 V and for silicon is 0.7 V.Therefore there will be no conduction of current.

Question # 7

What is photodiode?Write down its two main applications.

Ans 1: Photodiode is used for the detection of light.It is used in reverse biased state.Reverse current increase with the intensity of incident light.When no light incidents then reverse current will be negligble.It is used as
1. Detection of both visible and and invisible radiations
2. Automatic switching

Question # 8

Why the base current is transistor is very small?

Ans 1: Base is very thin so a number of electrons attracted by collector and very few enter into the base.And base current is very small.

Question # 9

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

Ans 1: For the normal operation the base emitter junction of transistor is forward biased and collector base junction is reverse biased.

Question # 10

How is the XOR gate so called?

Ans 1: One of its most commonly used applications is as a basic logic comparator which produce a logic "1" output when its two inputs bits are not equal.Because of the ,the XOR gate has an inequality status being known as an odd functions.

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

Set 1

10 Questions
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Set 2

10 Questions
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Set 3

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

Question # 1

What is semiconductor diode?

Ans 1: p-n junction is called semiconductor diode.

Question # 2

How the current flows in forward and reverse biased diode?

Ans 1: In forward biasing,the external potential difference supplies energy to free electrons in n-region and holes in p-region to overcome the potential barrier,a current of the orderof a few milli-amperes begins to flow across the pn junction.
In reverse biasing ,no current flow due to the majority charge carrier,However a very small current of the order of of few micro amperes flow across the junction due to minority charge carriers.It is also known as reverse current or leakage current.

Question # 3

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 # 4

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 # 5

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 # 6

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

Ans 1: Yes when anode is 0.2V positive with respect to cathode,it is forward biased.But the value of potential barrier for germanium is 0.3 V and for silicon is 0.7 V.Therefore there will be no conduction of current.

Question # 7

What is photodiode?Write down its two main applications.

Ans 1: Photodiode is used for the detection of light.It is used in reverse biased state.Reverse current increase with the intensity of incident light.When no light incidents then reverse current will be negligble.It is used as
1. Detection of both visible and and invisible radiations
2. Automatic switching

Question # 8

Why the base current is transistor is very small?

Ans 1: Base is very thin so a number of electrons attracted by collector and very few enter into the base.And base current is very small.

Question # 9

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

Ans 1: For the normal operation the base emitter junction of transistor is forward biased and collector base junction is reverse biased.

Question # 10

How is the XOR gate so called?

Ans 1: One of its most commonly used applications is as a basic logic comparator which produce a logic "1" output when its two inputs bits are not equal.Because of the ,the XOR gate has an inequality status being known as an odd functions.

Submit

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

Question # 1

What is AND Gate?

Ans 1: It is a logic gate that implements the truth table of AND operations.It has two or more input and single output.

Question # 2

Why the base current is transistor is very small?

Ans 1: Base is very thin so a number of electrons attracted by collector and very few enter into the base.And base current is very small.

Question # 3

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 # 4

Why is the photodiode operated in reverse biased state?

Ans 1: Photodiode is used for the detection of light.So it is used in reverse biased state.Reverse current increase with the intensity of incident light.When no light incidents,then reverse current will be negligible.

Question # 5

What is meant by rectification?

Ans 1: The conversing of alternating current signal into pulsating direct current signal is called rectification.The current for this purpose is called rectifier circuit.

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

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 # 8

Explain why an ordinary Silicon diode does not emit light.

Ans 1: Ordinary silicon is opaque to light,So it does not emit visible light.It emits infrared light.To emit light ,gallium arsenide or gallium arsenide photodiode are used as semiconductor.

Question # 9

What is principle of vital ground?

Ans 1: In an operational amplifier ,if the non inverting terminal is grounded by the concept of virtual ground the inverting terminal is also at ground potential though there is no physical connection between the inverting terminal and the ground,This is the principle of virtual ground.

Question # 10

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

Ans 1: For the normal operation the base emitter junction of transistor is forward biased and collector base junction is reverse biased.

Submit

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

Question # 1

How is the XOR gate so called?

Ans 1: One of its most commonly used applications is as a basic logic comparator which produce a logic "1" output when its two inputs bits are not equal.Because of the ,the XOR gate has an inequality status being known as an odd functions.

Question # 2

Why the base current is transistor is very small?

Ans 1: Base is very thin so a number of electrons attracted by collector and very few enter into the base.And base current is very small.

Question # 3

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 # 4

How the current flows in forward and reverse biased diode?

Ans 1: In forward biasing,the external potential difference supplies energy to free electrons in n-region and holes in p-region to overcome the potential barrier,a current of the orderof a few milli-amperes begins to flow across the pn junction.
In reverse biasing ,no current flow due to the majority charge carrier,However a very small current of the order of of few micro amperes flow across the junction due to minority charge carriers.It is also known as reverse current or leakage current.

Question # 5

Define Depletion region?

Ans 1: A region in a semiconductor device,usually at the junction of p-type and n-type materials ,in which there is neither an excess of electrons nor of holes is called depletion region,It charge less region.

Question # 6

Define Open Loop gain of operational amplifier.

Ans 1: The ratio of output voltage to voltage difference between non -inverting and inverting inputs ,when there is no external connection between the input and output is called open loop gain of operational amplifier.

Question # 7

What is photodiode?Write down its two main applications.

Ans 1: Photodiode is used for the detection of light.It is used in reverse biased state.Reverse current increase with the intensity of incident light.When no light incidents then reverse current will be negligble.It is used as
1. Detection of both visible and and invisible radiations
2. Automatic switching

Question # 8

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

Question # 9

Why is the photodiode operated in reverse biased state?

Ans 1: Photodiode is used for the detection of light.So it is used in reverse biased state.Reverse current increase with the intensity of incident light.When no light incidents,then reverse current will be negligible.

Question # 10

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.

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ICS Part 2 Physics Chapter 18 Short Questions Preparation

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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

What is semiconductor diode?

How the current flows in forward and reverse biased diode?

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

Write a note on LED.

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

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

What is photodiode?Write down its two main applications.

Why the base current is transistor is very small?

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

How is the XOR gate so called?

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

What is semiconductor diode?

How the current flows in forward and reverse biased diode?

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

Write a note on LED.

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

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

What is photodiode?Write down its two main applications.

Why the base current is transistor is very small?

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

How is the XOR gate so called?

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

What is AND Gate?

Why the base current is transistor is very small?

Why charge carriers are not present in the depletion region?

Why is the photodiode operated in reverse biased state?

What is meant by rectification?

Give any two characteristics of operational amplifier.

How is p-n junction formed?

Explain why an ordinary Silicon diode does not emit light.

What is principle of vital ground?

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

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

How is the XOR gate so called?

Why the base current is transistor is very small?

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

How the current flows in forward and reverse biased diode?

Define Depletion region?

Define Open Loop gain of operational amplifier.

What is photodiode?Write down its two main applications.

Give four application or uses of photodiode?

Why is the photodiode operated in reverse biased state?

What is photovoltaic cell?Discuss its working?

ICS Part 2 Physics Chapter 18 Short Questions Preparation

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