ICS Part 2 Physics Chapter 18 Short Questions Preparation

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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 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 # 2

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 # 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

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 # 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

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 # 7

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 # 8

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 # 9

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.

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 "

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Set 2

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

Question # 1

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 # 2

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 # 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

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 # 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

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 # 7

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 # 8

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 # 9

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.

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

Question # 1

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 # 2

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.

Question # 3

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 # 4

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 # 5

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 # 6

What do LED and LASER stand for?

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

Question # 7

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 # 8

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 # 9

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 # 10

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.

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

Question # 1

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 # 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

What is semiconductor diode?

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

Question # 4

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 # 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

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 # 7

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 # 8

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 # 9

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 # 10

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.

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

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

Why is the photodiode operated in reverse biased state?

Explain why an ordinary Silicon diode does not emit light.

Define Depletion region?

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

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?

How the normal operation of transistor is achieved?

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

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

Why is the photodiode operated in reverse biased state?

Explain why an ordinary Silicon diode does not emit light.

Define Depletion region?

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

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?

How the normal operation of transistor is achieved?

How is the XOR gate so called?

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

Define logic system and logic gates.

How the normal operation of transistor is achieved?

Give two applications of gated in control system.

What is photovoltaic cell?Discuss its working?

Differentiate between the forward biased and the reserve biase.

What do LED and LASER stand for?

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

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?

Write a note on LED.

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

Give four application or uses of photodiode?

Define logic system and logic gates.

What is semiconductor diode?

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

What is photovoltaic cell?Discuss its working?

What is photodiode?Write down its two main applications.

Why is the photodiode operated in reverse biased state?

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?

How the current flows in forward and reverse biased diode?

ICS Part 2 Physics Chapter 18 Short Questions Preparation

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