CBSE > Class 12 > Physics | CBSE Board | Homework Help

Ask questions which are clear, concise and easy to understand.

Ask Question

What is doppler's effect?

Posted by Srivinayak V 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 7 years, 3 months 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.

2Thank You

ANSWER

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

Posted by Riya Bisht 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Anjali Attri 7 years, 3 months 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

0Thank You

ANSWER

Convert nand to nor gate

Posted by Amol Agarwal 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

O Singh 7 years, 3 months ago

Use 2 not gates and 1 nand gate

1Thank You

ANSWER

What is monochromatic light?

Posted by Annu Annu 7 years, 3 months ago

CBSE > Class 12 > Physics

2 answers

Pushpendra Pratap Singh 7 years, 3 months ago

Single wavelenth and single colour

1Thank You

Kartikey Joshi 7 years, 3 months ago

It Means Single Coloured Light

2Thank You

ANSWER

Derivation of ac generator

Posted by Agrim Jain 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Amit Kumar 7 years, 3 months ago

1Thank You

ANSWER

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, 3 months ago

CBSE > Class 12 > Physics

1 answers

Anjali Attri 7 years, 3 months 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

0Thank You

ANSWER

What is new paper pattern

Posted by Dinesh Jatav 7 years, 3 months ago

CBSE > Class 12 > Physics

3 answers

Aryan Rai 7 years, 3 months ago

Oops i realised it now?

0Thank You

Mansi Sharma 7 years, 3 months ago

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

0Thank You

Aryan Rai 7 years, 3 months ago

Which subject?

0Thank You

ANSWER

How many numbers of numericals will come to exam paper

Posted by Dinesh Jatav 7 years, 3 months ago

CBSE > Class 12 > Physics

2 answers

Kuldeep Singh 7 years, 3 months ago

15 number

0Thank You

Mansi Sharma 7 years, 3 months ago

About 15 marks are reserved for the numericals .

1Thank You

ANSWER

what do you mean by conservation of charge

Posted by Akash Roy 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Srivinayak V 7 years, 3 months ago

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

2Thank You

ANSWER

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

Posted by Prakash Singh 7 years, 3 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is a half wave rectifier

Posted by Afzal Habib 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Anjali Attri 7 years, 3 months ago

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

0Thank You

ANSWER

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

Posted by Deepak Chand Ramola 7 years, 3 months ago

CBSE > Class 12 > Physics

7 answers

O Singh 7 years, 3 months ago

SL Arora best book

1Thank You

Drake Verma 7 years, 3 months 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, 3 months ago

Ncert and To the point

1Thank You

Aryan Rai 7 years, 3 months ago

NCERT and DC pandey

1Thank You

Mansi Sharma 7 years, 3 months ago

I also recommend SL Arora and ncert.

3Thank You

Srivinayak V 7 years, 3 months ago

SL Arora

2Thank You

Ashish Shrivas 7 years, 3 months ago

Ncert & u like sample

1Thank You

ANSWER

What is a cyclotron principal and uses of it

Posted by Nitish Bamrara 7 years, 3 months ago

CBSE > Class 12 > Physics

2 answers

Nitish Bamrara 7 years, 3 months ago

What charge negative,positive and both?

0Thank You

Nitin Yadav 7 years, 3 months 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

2Thank You

ANSWER

Explain Right hand palm rule .

Posted by Arti Vishwakarma 7 years, 3 months ago

CBSE > Class 12 > Physics

2 answers

Khelan Singh 7 years, 3 months 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, 3 months 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

1Thank You

ANSWER

Explain Kirchoff's low .

Posted by Arti Vishwakarma 7 years, 3 months ago

CBSE > Class 12 > Physics

2 answers

Aryan Rai 7 years, 3 months ago

leaving*

0Thank You

Mansi Sharma 7 years, 3 months 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 .

3Thank You

ANSWER

State the working principle of dynamo?

Posted by Srivinayak V 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Arti Vishwakarma 7 years, 3 months 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.

2Thank You

ANSWER

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

Posted by Srivinayak V 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Mansi Sharma 7 years, 3 months 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 .

2Thank You

ANSWER

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

Posted by Arti Vishwakarma 7 years, 3 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is the use of external load in photodiode?

Posted by Abhi Paul 7 years, 3 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Potensometer

Posted by Aman Bansal 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Nitika Neb 7 years, 3 months 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.

0Thank You

ANSWER

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

Posted by Mohd Danish 7 years, 3 months ago

CBSE > Class 12 > Physics