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

Work function =it is the minimum amount of energy required to just emitt electron from metal surface. Or emission=the liberation of free electron from metal surface

1Thank You

Vikas Semwal 6 years, 5 months ago

Work function is energy for liberating electron from atom and kE is the energy used for emission

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What exactly is mass ?

Posted by Yashveer Singh 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

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Q1 name one method each for 1: production 2: detection of x rays Q2 state the principal of production of em wave Q3 what does an em wave consist on what fectors does its velocity in vaccum depend Q4 which part of em spectrum has largest penetration power Q5 radiowaves and gammarays ar waves both are transerve in nature and em is character and have same speed in vaccum in which aspect they are different

Posted by Kawal Rai 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

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What is rotational motion chapter

Posted by Laxman Khedkar 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Kawal Rai 6 years, 5 months ago

For example, the wheel of the car or train is in constant rotational motion. Rotational motion is a kind of motion in which the body follows a curved path. For example, the wheel of the car or train is in constant rotational motion. In a linear motion, a body follows straight paths.

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Does an isolate magnetic pole exist like an isolate electric charge?

Posted by Raman Deep 6 years, 5 months ago

CBSE > Class 12 > Physics

4 answers

Raheem Hasan 6 years, 4 months ago

No.. Bro

0Thank You

Yashveer Singh 6 years, 5 months ago

No because it is a hypothetical concept which can be used to understand magnetism in simple ways

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Mritunjay Dubey 6 years, 5 months ago

No because monopole doesnot exist

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Raman Brar 6 years, 5 months ago

No there is no monopoles.

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What is the nature of the electric field lines of uniform electric field

Posted by Gursharn Kaur 6 years, 5 months ago

CBSE > Class 12 > Physics

3 answers

Ravi Yadav 6 years, 4 months ago

Parallel equispaced

0Thank You

Vikas Semwal 6 years, 5 months ago

Higher potential to lower potential

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Yashveer Singh 6 years, 5 months ago

All the electric field lines are equidistance from each other or simply they are unifomly distributed in space ( flux is constant )

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The electric force between two charges separated certain is F . If the distance between both charges becomes double then what is the effect on forcw between them

Posted by Yugratan Kumar 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Ravi Yadav 6 years, 4 months ago

It will decrease by 1/4

1Thank You

Yashveer Singh 6 years, 5 months ago

Force is reduced by 4 times because force is inversly proportional to r^2

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The electric force between two point charges in air is 16×10^-5 N . And the electric force between same charges in a glass slab id 4×10^-5 N . Calculate thr dielectric constant of glass slab

Posted by Yugratan Kumar 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Ravi Yadav 6 years, 4 months ago

K=4

1Thank You

Sajid Ali 6 years, 4 months ago

The dielectric const is 4.

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what is main experiment in practical of class 12

Posted by Ankit Raj 6 years, 5 months ago

CBSE > Class 12 > Physics

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A small candle 2.5cm is size is placed 27cm in front of concave mirror of radius of curvature 36 cm at what distance from the mirror should a screen be place in order to recieve a sharp image discribe the nature and size of image

Posted by Satish Pal 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Satish Pal 6 years, 5 months ago

V=-54and m=-2

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What is the smallest unit of k

Posted by Saksham Sharma 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Saksham Sharma 6 years, 5 months ago

1because k cannot be smaller than one

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Charge is associated with mass why

Posted by Rishabh Soni 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Ravi Yadav 6 years, 4 months ago

Bcz its converse is not true

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Draw one equipotential surface due to uniform electric field

Posted by Sunil Singh 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

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Using gauss theorem prove coulumb law

Posted by Guddu Kumar 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

F=r/2. Proove that.

Posted by Sangam Martand 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Ravi Yadav 6 years, 4 months ago

Force will be 4 times

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1/f = 1/v+1/u. Proove that

Posted by Sangam Martand 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 6 years, 5 months ago

The formula is a relation between the object distance u , inmage distance v and the focal length from the pole of the concave mirror. The formula is valid for the images in convex mirror and even for the images in lens.

We consider the image formed by aconcave mirror whose focal length is f and whose radius of curvature is r = 2f.

Let P be the pole of the concave mirror. Let P, F , C be the pole, focucal point , and centre of curvature along principal axis . So, PC = 2PF , as r = 2f.
Let AB be a vertically standinding object beyond C on the principal axis.

Then the ray starting from B parallel to principal axis incident on the mirror at D reflects through the focus F. Let the reflected ray be CFB' .

The another ray starting from B through the centre C incident on the mirror at E retraces its path by reflection being normal to the mirror.
Now BE and DF produced meet at B'.

Now drop the perpendicular from B' to PC to meet at A'.

Drop the perpendicular from D to PC to meet at G.

Now PF = f , the focal length. PA = u object distance from the mirror. PA' = v the image distance.

Now consider the similar triangles ABC and A'BC.

AB/AB' = AC/ A'C =( PU-PC)(PC-PA') = (u-2f)/((2f-v).....(1)

Consider the similar triangles DFG and A'B'F.

DG/A'B' = PF/PA' PF/(PA'-PF)= f/(v-f)... (2)

DG = AB. So (2) could be rewritten as:

AB/A'B' + f/v ....................(3).

From (2) and (3), LHS being same , we can equate right sides.

(u-2f)/(2f-v) = f/(v-f).

(u-2f)(v-f) = (2f-v)f.
uv-2fv -fu +2f^2 = 2f^2 -fv

uv = fu +fv

Dvide by uvf;

1/f = 1/v+1/u.

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What is the formula of work function

Posted by Ashish Rajput 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Sajid Ali 6 years, 4 months ago

W°=hv-K.E

0Thank You

Nisha Kaushik 6 years, 5 months ago

Work func.= Plank's constant×frequency- kinetic energy.

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What a pattern of objective question

Posted by Aryan Jauswal 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Vivekanand Yadav 6 years, 5 months ago

It will consist of very short question,3assertion reason question and left question are objective question.

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ANSWER

What is hysteresis?

Posted by Aarav Tripathi 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Vivekanand Yadav 6 years, 5 months ago

The lagging of magnetic material behind magnetic field is called hystris.

2Thank You

Yogita Ingle 6 years, 5 months ago

The word hysteresis means lagging behind. The phenomenon of lagging of intensity of magnetisation (M) behind magnetic intensity (H), when a specimen of magnetic material is subjected to a cycle of magnetization is called hysteresis.

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