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What is doppler's effect?

Posted by Srivinayak V 7 years ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 7 years ago

Doppler Effect is the shift in frequency of light when there is relative motion between the source and observer.
It is used to measure the speed of a receding object.
When the source is moving away from the observer then the wavefronts have to travel a greater distance to reach the observer.
When a star is moving away from the earth the wavelength in the middle of the visible region of the spectrum moves towards the red end of the spectrum.
As a result star looks more reddish when moves away from the earth.

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What is doping?write various method to dope semi conductor with impurity

Posted by Riya Bisht 7 years ago

CBSE > Class 12 > Physics

1 answers

Anjali Attri 7 years ago

Addition of impurities to any pure substance is called doping .various method of doping are_ 1. Add impurity atom in melt form of semiconductor.2. Implant the dopant atom by bombarding semiconductor with their ion

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Convert nand to nor gate

Posted by Amol Agarwal 7 years ago

CBSE > Class 12 > Physics

1 answers

O Singh 7 years ago

Use 2 not gates and 1 nand gate

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What is monochromatic light?

Posted by Annu Annu 7 years ago

CBSE > Class 12 > Physics

2 answers

Pushpendra Pratap Singh 7 years ago

Single wavelenth and single colour

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Kartikey Joshi 7 years ago

It Means Single Coloured Light

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Derivation of ac generator

Posted by Agrim Jain 7 years ago

CBSE > Class 12 > Physics

1 answers

Amit Kumar 7 years ago

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Derive an expression for energy stored in a parallel plate capacitor with air as the medium between its plate?

Posted by Sashank Duggal 7 years ago

CBSE > Class 12 > Physics

1 answers

Anjali Attri 7 years ago

As V=Q/C. Let dW be small amount of work done . Therefore,dW = V× dQ Integrating both sides,we get W= 1/C×Q× Q/2 =Q×Q/2C

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What is new paper pattern

Posted by Dinesh Jatav 7 years ago

CBSE > Class 12 > Physics

3 answers

Aryan Rai 7 years ago

Oops i realised it now?

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Mansi Sharma 7 years ago

It is written in the end physics ...dude!

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Aryan Rai 7 years ago

Which subject?

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How many numbers of numericals will come to exam paper

Posted by Dinesh Jatav 7 years ago

CBSE > Class 12 > Physics

2 answers

Kuldeep Singh 7 years ago

15 number

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Mansi Sharma 7 years ago

About 15 marks are reserved for the numericals .

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what do you mean by conservation of charge

Posted by Akash Roy 7 years ago

CBSE > Class 12 > Physics

1 answers

Srivinayak V 7 years ago

Charge can be neither be created nor be destroyed,it can only be converted.

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How we can prove that guss law are applicable for closed loop only?

Posted by Prakash Singh 7 years ago

CBSE > Class 12 > Physics

0 answers

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What is a half wave rectifier

Posted by Afzal Habib 7 years ago

CBSE > Class 12 > Physics

1 answers

Anjali Attri 7 years ago

A rectifier which convert half AC wave signal to DC signal is called half wave rectifier.

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Which book would you recommend for practicing for physics examination??

Posted by Deepak Chand Ramola 7 years ago

CBSE > Class 12 > Physics

7 answers

O Singh 7 years ago

SL Arora best book

1Thank You

Drake Verma 7 years ago

I won't recommend ncert just get stuck to a reference book like pradeep,sl arora or any one with whom u r comfortable...in ncert explanation is not upto the mark

2Thank You

Adarsh Gupta 7 years ago

Ncert and To the point

1Thank You

Aryan Rai 7 years ago

NCERT and DC pandey

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Mansi Sharma 7 years ago

I also recommend SL Arora and ncert.

3Thank You

Srivinayak V 7 years ago

SL Arora

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Ashish Shrivas 7 years ago

Ncert & u like sample

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What is a cyclotron principal and uses of it

Posted by Nitish Bamrara 7 years ago

CBSE > Class 12 > Physics

2 answers

Nitish Bamrara 7 years ago

What charge negative,positive and both?

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Nitin Yadav 7 years ago

Principle- the frequency of revolution doesn't depend on the energy of the charged particle. Uses- used to accelerate charged particle with very high speed

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Explain Right hand palm rule .

Posted by Arti Vishwakarma 7 years ago

CBSE > Class 12 > Physics

2 answers

Khelan Singh 7 years ago

In right hand palm rule the top of thumb represent the current and curling fingers represent the magnetic field

1Thank You

Nitika Neb 7 years ago

The right hand rule states that, to find the direction of the magnetic force on a positive moving charge, the thumb of the right hand point in the direction of v, the fingers in the direction of B, and the force (F) is directed perpendicular to the right hand palm

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Explain Kirchoff's low .

Posted by Arti Vishwakarma 7 years ago

CBSE > Class 12 > Physics

2 answers

Aryan Rai 7 years ago

leaving*

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Mansi Sharma 7 years ago

Kirchoff's law is used to solve the complex electric circuit. It states that the alegbraic sum of all the current meeting at a point or junction in close electric circuit is 0 .Sum of all current entering any point of junction must be equal to the sum of current leading that point or junction .

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State the working principle of dynamo?

Posted by Srivinayak V 7 years ago

CBSE > Class 12 > Physics

1 answers

Arti Vishwakarma 7 years ago

Working: 1. when armature rotates with its axis perpendicular to magnetic field , the magnetic flux linking to the coil changes and an emf is induced in the coil. Therefore an induced current flows in the coil and in the external circuit connected to the coil through brushes and the slip rings. 2, The plane of coil rotates such that the arm AD goes down the plane of paper, and the arm BC becomes above the plane of paper. 3. Using Fleming's Right hand rule, we find that the current flows in the direction of CBAD and in the outer circle from Brush B2 To B1. 4. After half a rotation, the arm Bc goes down and the arm AD goes above.Using Fleming's Right hand rule, the current flows in the direction DABC and in outer circuit from brush B1 to B2. 5. Thus during half a rotation of coil, current flows in one direction and next half of rotation , current flows in the opposite direction. This process repeats and AC current flows in the external circuit.

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Difference between magnetic moment and magnetic dipole moment ? moving charges and magnetism

Posted by Srivinayak V 7 years ago

CBSE > Class 12 > Physics

1 answers

Mansi Sharma 7 years ago

Magnetic dipole moment is defined as the product of magnitude of charge and the sepration distance b/ w them . Magnetic moment is quantity that represents the magnetic strength and orientation of a magnet or the other object that produces the magnetic field .

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Give the reasons why modulation of a message signal is necessary for long distance transmission ?

Posted by Arti Vishwakarma 7 years ago

CBSE > Class 12 > Physics

0 answers

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What is the use of external load in photodiode?

Posted by Abhi Paul 7 years ago

CBSE > Class 12 > Physics

0 answers

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Potensometer

Posted by Aman Bansal 7 years ago

CBSE > Class 12 > Physics

1 answers

Nitika Neb 7 years ago

Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick. Potentiometers are rarely used to directly control significant power (more than a watt), since the power dissipated in the potentiometer would be comparable to the power in the controlled load.

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How does angle of dip changes as one goes from magnetic pole to magnetic equator of the earth?

Posted by Mohd Danish 7 years ago

CBSE > Class 12 > Physics