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

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

What is semiconductor diode?

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

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

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 # 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

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 # 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

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 # 10

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.

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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?

What is photovoltaic cell?Discuss its working?

What is semiconductor diode?

Write a note on LED.

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?

How is the XOR gate so called?

Why the base current is transistor is very small?

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

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

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?

What is photovoltaic cell?Discuss its working?

What is semiconductor diode?

Write a note on LED.

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?

How is the XOR gate so called?

Why the base current is transistor is very small?

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

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 2

Why is the photodiode operated in reverse biased state?

What is semiconductor diode?

What is principle of vital ground?

What is meant by rectification?

Define current of gain of a transistor

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

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

Give four application or uses of photodiode?

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

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

Give four application or uses of photodiode?

How is p-n junction formed?

Differentiate between the forward biased and the reserve biase.

Why the base current is transistor is very small?

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

What is principle of vital ground?

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?

What do LED and LASER stand for?

What is AND Gate?

ICS Part 2 Physics Chapter 18 Short Questions Preparation

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