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

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

Ask Question

What is dirft velocity??

Posted by Nandita Osaniya 6 years, 11 months ago

3 answers

Priya Singh 6 years, 11 months ago

When electric field is given in any conductor then the free electrons moves in opposite direction of applied electric field. The velocity of electron due to applied electric field is known as drift velocity.

0Thank You

Yogita Ingle 6 years, 11 months ago

The average velocity gained by the free electrons of a conductor in the opposite direction of the externally applied electric field is called Drift Velocity.
Charged particles do not travel in a straight line through a conductor, because they collide with other particles in the material. We therefore use the average speed the particle travels at along the conductor. This is called the drift velocity.

0Thank You

Anam Fatima 6 years, 11 months ago

The average velocity with which free electrons in a conductor get drifted in a particular direction under the influence of external field

0Thank You

ANSWER

Chapter 3 (pradeep's book) me earth magnet wala portion kitna wieghtage rakhta hai

Posted by Mayank K. Mahour 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Vinkal Kamboj 6 years, 11 months ago

This chapter is not important only do hysterious loop

1Thank You

ANSWER

How much percent question are match from cbse sample paper of class 12

Posted by Md Farhan Niyaz 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Nitika Neb 6 years, 11 months ago

20%

4Thank You

ANSWER

What do you mean by power factor on what factors it depends

Posted by Manali Shinde 6 years, 11 months ago

CBSE > Class 12 > Physics

2 answers

Harisha Goothy 6 years, 11 months ago

V and i ..are the 2 factors

0Thank You

Devesh Chaturvedi 6 years, 11 months ago

The ratio of resistance to the impedance of the circuit is known as power factor.

3Thank You

ANSWER

Sample paper 2018_2019 questions no 16 solution

Posted by Neha Hansraj 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Tej Pratap Singh 6 years, 11 months ago

Alternati g

0Thank You

ANSWER

Binding energy curve diagram

Posted by Anjali Yadav 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Ishaan Verma 6 years, 11 months ago

Can't send images

1Thank You

ANSWER

Is the topic "electric field intensity at a point on the axis of circular chareged ring" is in syllabus

Posted by Abc Kamboz 6 years, 11 months ago

CBSE > Class 12 > Physics

2 answers

Vinkal Kamboj 6 years, 11 months ago

Not for 12 but if u r preparing for iit than u have to do

0Thank You

Nitika Neb 6 years, 11 months ago

Yes , it's in the syllabus

2Thank You

ANSWER

Draw a graph showing variation of resistance of a metal wire and functions of its diameter keeping its length and material constant

Posted by Prahlad Soni 6 years, 11 months ago

CBSE > Class 12 > Physics

3 answers

Nitika Neb 6 years, 11 months ago

https://www.sarthaks.com/59642/plot-graph-showing-the-variation-of-resistance-of-conducting-wire-as-function-its-radius You can see in this link

2Thank You

Nitika Neb 6 years, 11 months ago

|. \ |. \ |. \_____ |_________________ The graph will be like this , hope you will understand

0Thank You

Nitika Neb 6 years, 11 months ago

Resistance of a conductor of length l, and radius r is given by

0Thank You

ANSWER

What is the direction of the force acting along a charged particle q ,moving with a velocity v and a uniform magnetic field B?

Posted by Sagar Samanta 6 years, 11 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

How to make converging lens to diverging lens?

Posted by Sahil Naik 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Nitin Yadav 6 years, 11 months ago

By using a medium having refractive index more than the lens

1Thank You

ANSWER

Gass theorem

Posted by Sahnawaz Hussain 6 years, 11 months ago

CBSE > Class 12 > Physics

3 answers

Nitika Neb 6 years, 11 months ago

The net flux through a closed surface is directly proportional to the net charge in the volume enclosed by the closed surface. Φ = →E.d→A = qnet/ε0

0Thank You

Tanisha Saini 6 years, 11 months ago

There are two gauss theorems One electric Second magnetic Which one do you wany

0Thank You

Yo Yo Honey Singh ? 6 years, 11 months ago

What is Gass theorem❓ there is no Gass theorem in physics. It is Gauss Theorem

0Thank You

ANSWER

Find tha total energy stored in the capacitor in the given network

Posted by Vaish Thakur 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Mohit Sepat 6 years, 11 months ago

Given ???

2Thank You

ANSWER

How to revise modern physics i know its easy but taking too much time n i am loosing my confidence

Posted by Deepa Shree 6 years, 11 months ago

CBSE > Class 12 > Physics

3 answers

Tanisha Saini 6 years, 11 months ago

Study from ncert it would be easier

0Thank You

H!Mαη$Hμ Ұαδαυ ✔️ 6 years, 11 months ago

0Thank You

Ash Thunderbird ✔ 6 years, 11 months ago

Aao kbhi... Hamare school mein. Usi ke revision chal rhe h ?

0Thank You

ANSWER

How to determine resistance per cm of a given wire by ploting a graph of potential diffrence versus current?

Posted by Neeraj Kumar 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Ayush Kumar Gupta 6 years, 11 months ago

Slope of the graph gives resistance

1Thank You

ANSWER

Why photoelectric effect can not be explained on the basis of wave nature of light .

Posted by Prabhat Yadav. Vikash 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Ash Thunderbird ✔ 6 years, 11 months ago

According to wave physics, energy of a wave depends upon amplitude of a wave. It means that light of any frequency can make electrons come out from metal but it do not happens, light of certain fixed frequency can make electrons come out from metal. So, the photoelectric effect can only be explained by particle nature of light not wave.

3Thank You

ANSWER

How helical path obtained explain

Posted by Ayush Agarwal 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

H!Mαη$Hμ Ұαδαυ ✔️ 6 years, 11 months ago

Because of vcosθ it undergoes linear motion and because of vsinθ it show circular motion and these two motion results in helical motion

2Thank You

ANSWER

A wire whose cross sectional area is increasing linearly from its one end to the other, is connected across a battery of v volts. Which of the following quantities remain constant in wire? a. Drift velocity. b. Current density. c. Electric current d. Electric field. Justify your answer.

Posted by Tanisha Rawat 6 years, 11 months ago

CBSE > Class 12 > Physics

2 answers

H!Mαη$Hμ Ұαδαυ ✔️ 6 years, 11 months ago

justification » a) v=qEζ/m which is independent of area b) j=nev c) I=neAv d) E=Vd

0Thank You

H!Mαη$Hμ Ұαδαυ ✔️ 6 years, 11 months ago

a) b) and d) will remain constant

1Thank You

ANSWER

A dipole is made up of two charge +q and-q separated by a distance 2a. Derive an expression fo electric fiwld E due do this dipole at a point distance r from the centre of the dipole on the equatorial plane.

Posted by Soren Jami 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Sivabrat Mohanty Sir 6 years, 11 months ago

Refer any standard book Like s.l . arora

0Thank You

ANSWER

Why do we use concave magnetic poles in a galvanometer

Posted by Raji Priya 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Ishan Rana 6 years, 11 months ago

To provide radial mag. Field

1Thank You

ANSWER

Light from the sun is unpolarised.Explain how does sunlight gets polarized by the process of scattering ? Justify the statement in 3 marks

Posted by Mohit Garg 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 6 years, 11 months ago

When unpolarized light falls on a refracting mediumsome part of the light is refracted and some part is reflected.These refracted and reflected light are partially polarized and areseperated by an angle of π2.The reflected polarized light is called polarization by scattering.

2Thank You

ANSWER

Its very dificult to study all the chapters...so i want to know that how many chapter i should study to get pass only? And which chapter carry the maximum marks?

Posted by Vishal Sha 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Ekta Gupta Ekta 6 years, 11 months ago

Wave optics and ray optics carry maximum mark if you want to pass then read communication system and ac genrator or their so many chapters which is theoratical

2Thank You

ANSWER

A point charge +Q is placed in the vicinity of conducting surface . Draw the electric feild lines between the surface and the charge

Posted by Roopal Ranjan 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Ekta Gupta Ekta 6 years, 11 months ago

When +q charged placed in the vicnity nearby tje conducting surface polarisation of charge take place within the conducting surface charge arrange themselv inside the conducting surface as negative charges aliggn themselv towards the direction of +q charge

3Thank You

ANSWER

The objective lensesof two telescopehave the same apertures but thier focal lengths are in the same ratio 1:2compare the resolving power of two telescope

Posted by Ekta Gupta Ekta 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Nitin Yadav 6 years, 11 months ago

2:1

0Thank You

ANSWER

Write a relation for polarization P of a dielectric material in the presence of an external electric field E

Posted by Kirandeep Kaur 6 years, 11 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 11 months ago

Relation between polarisation , P of dielectric material in the presence of external electric field , E is given by
P = χε₀.E
Here χ is the susceptibility of medium
ε₀ is the permittivity of medium{ e.g, free space }
and E is the electric field intensity.

1Thank You

ANSWER

Physics me kisi chapter ko skip nhi kar sakte kya ???

Posted by Surbhi . 6 years, 11 months ago

CBSE > Class 12 > Physics

4 answers

Nisha Singh 6 years, 11 months ago

dual nature of matter and radiation

1Thank You

Nisha Singh 6 years, 11 months ago

Em waves

2Thank You

Arunima Sharma 6 years, 11 months ago

Kyun .....ip h toh ....phy.m score nhi krna hota h kya ?

2Thank You

Mansi Sharma 6 years, 11 months ago

Yaa! Em waves and communication system if u have opted IP.

3Thank You

ANSWER

Why current of holes are considered in the intrinsic semiconductor? While the holes are only assumptions.

Posted by Avinash Sharma 6 years, 11 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is chromatic abberation

Posted by Gyandeep Srivastava 6 years, 11 months ago

CBSE > Class 12 > Physics

2 answers

Gyandeep Srivastava 6 years, 11 months ago

Thank u a lot...

0Thank You

Yogita Ingle 6 years, 11 months ago

Defect of the lens by which it is unable to bring the rays of different colour to focus at a single point. Image of a white object formed by lens is usually coloured and blurred. This defect of the image produced by lens is called chromatic aberration.

1Thank You

ANSWER

Current gain foemula

Posted by Yuvaraj Baskar 6 years, 11 months ago

CBSE > Class 12 > Physics