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

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 # 2

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 # 3

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 # 4

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

Ans 1: The potential difference across the depletion region which acts as a barrier to the flow of charge carriers is called potential barrier.The value of potential barrier for germanium is 0.3V and for silicon is 0.7 V.

Question # 5

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 # 6

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 # 7

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 # 8

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 # 9

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 # 10

How the normal operation of transistor is achieved?

Ans 1: For the normal operation the base emitter junction of transistor is forward biased and collector base junction is reverse.
In a common emitter amplifier ,input signal is applied between base and emitter and output signal is taken across collector and emitter,Similarly emitter base junction is forward biased and collector base junction is reverse biased.

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

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Set 2

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

Question # 1

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 # 2

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 # 3

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 # 4

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

Ans 1: The potential difference across the depletion region which acts as a barrier to the flow of charge carriers is called potential barrier.The value of potential barrier for germanium is 0.3V and for silicon is 0.7 V.

Question # 5

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 # 6

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 # 7

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 # 8

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 # 9

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 # 10

How the normal operation of transistor is achieved?

Ans 1: For the normal operation the base emitter junction of transistor is forward biased and collector base junction is reverse.
In a common emitter amplifier ,input signal is applied between base and emitter and output signal is taken across collector and emitter,Similarly emitter base junction is forward biased and collector base junction is reverse biased.

Submit

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

Question # 1

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 # 2

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 # 3

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 # 4

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 # 5

What is semiconductor diode?

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

Question # 6

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 # 7

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 # 8

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 # 9

Give two applications of gated in control system.

Ans 1: Gates are widely used in control system.They control the function of the system by monitoring some physical parameters such as temperature ,pressure or some other physical quantity of the system,Sensors are required to operate gates.

Question # 10

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.

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

Question # 1

What is semiconductor diode?

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

Question # 2

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 # 3

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

Ans 1: When forward biased then the width of depletion region decreases and when reverse biased then the width of depletion region increase.

Question # 4

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 # 5

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 # 6

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 # 7

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 # 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 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

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.

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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

Define Open Loop gain of operational amplifier.

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

Why is the photodiode operated in reverse biased state?

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

Explain why an ordinary Silicon diode does not emit light.

How is p-n junction formed?

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

Define Depletion region?

What is photodiode?Write down its two main applications.

How the normal operation of transistor is achieved?

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

Define Open Loop gain of operational amplifier.

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

Why is the photodiode operated in reverse biased state?

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

Explain why an ordinary Silicon diode does not emit light.

How is p-n junction formed?

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

Define Depletion region?

What is photodiode?Write down its two main applications.

How the normal operation of transistor is achieved?

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

Define current of gain of a transistor

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

Give four application or uses of photodiode?

How is the XOR gate so called?

What is semiconductor diode?

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

What is meant by rectification?

What is photovoltaic cell?Discuss its working?

Give two applications of gated in control system.

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

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

What is semiconductor diode?

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

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

Differentiate between the forward biased and the reserve biase.

Define current of gain of a transistor

How the current flows in forward and reverse biased diode?

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

Why the base current is transistor is very small?

Why is the photodiode operated in reverse biased state?

Define Depletion region?

ICS Part 2 Physics Chapter 18 Short Questions Preparation

12th Class Physics
Short Questions Preparation