ICS Part 2 Physics Chapter 18 Short Questions Preparation

Question # 1

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 # 2

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 # 3

What is OP-GATE?

Ans 1: OR-GATE implements the logic of OR operation.It has two or more inputs and a single output.Its output will be zero only when all the inputs are zero.

Question # 4

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 # 5

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 # 6

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 # 7

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 # 8

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 # 9

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 # 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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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 principle of vital ground?

Define Open Loop gain of operational amplifier.

What is OP-GATE?

What is photodiode?Write down its two main applications.

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?

How the current flows in forward and reverse biased diode?

Write a note on LED.

Define current of gain of a transistor

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

What is principle of vital ground?

Define Open Loop gain of operational amplifier.

What is OP-GATE?

What is photodiode?Write down its two main applications.

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?

How the current flows in forward and reverse biased diode?

Write a note on LED.

Define current of gain of a transistor

How the normal operation of transistor is achieved?

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

How is the XOR gate so called?

Explain why an ordinary Silicon diode does not emit light.

Give four application or uses of photodiode?

Define logic system and logic gates.

Why is the photodiode operated in reverse biased state?

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

Define Depletion region?

Define Open Loop gain of operational amplifier.

What is meant by rectification?

What is photodiode?Write down its two main applications.

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

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?

Differentiate between the forward biased and the reserve biase.

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?

How is p-n junction formed?

What is principle of vital ground?

What is meant by rectification?

Define logic system and logic gates.

ICS Part 2 Physics Chapter 18 Short Questions Preparation

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