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

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 # 3

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 # 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

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 # 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

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 # 8

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 # 9

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 # 10

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.

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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?

What is photovoltaic cell?Discuss its working?

How the current flows in forward and reverse biased diode?

Explain why an ordinary Silicon diode does not emit light.

Write a note on LED.

Define Open Loop gain of operational amplifier.

Define logic system and logic gates.

How the normal operation of transistor is achieved?

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

Why charge carriers are not present in the depletion region?

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?

What is photovoltaic cell?Discuss its working?

How the current flows in forward and reverse biased diode?

Explain why an ordinary Silicon diode does not emit light.

Write a note on LED.

Define Open Loop gain of operational amplifier.

Define logic system and logic gates.

How the normal operation of transistor is achieved?

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

Why charge carriers are not present in the depletion region?

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

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

How is the XOR gate so called?

What is OP-GATE?

Explain why an ordinary Silicon diode does not emit light.

Why is the photodiode operated in reverse biased state?

Define Depletion region?

How the normal operation of transistor is achieved?

Why the base current is transistor is very small?

Give two applications of gated in control system.

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

Differentiate between the forward biased and the reserve biase.

How is the XOR gate so called?

What is principle of vital ground?

What is OP-GATE?

What is photovoltaic cell?Discuss its working?

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

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

What is meant by rectification?

What is AND Gate?

Explain why an ordinary Silicon diode does not emit light.

ICS Part 2 Physics Chapter 18 Short Questions Preparation

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