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

It was discovered by Henri Becquerel in 1895. However, term radioactivity was given by Madam Curie. Radioactivity being a natural nuclear phenomenon, remains unaffected by external factors like temperature, pressure etc. Potassium uranyl sulphate [K (UO₂) (SO₄)₂] was the first compound found to be radioactive.

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Anushka Singh 6 years, 5 months ago

The radioactivity was coined by marie Curie with her husband Pierre but actually phenomenon was discovered by Henri Becquerel

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Write dimensional formula of k and unit

Posted by Anushka Singh 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Nishu Sahu 6 years, 5 months ago

Unit- Newton meter sq per Coloumb sq D.F- ML^3T^-4A^-2

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Write dimensional formula of eff silent not standard

Posted by Anushka Singh 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Anushka Singh 6 years, 5 months ago

I got answer for this question

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Calculate the coulomb`s force between a proton and electron separated by0.8÷1000000000000000m.

Posted by Rahul Verma 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Nishu Sahu 6 years, 5 months ago

36 N

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Two identical conduncting ball A and B having -Q and +3Q charge respectively. They are bought in contact with each other and then separated by a distance d apart. Find the nature of the coulomb force between them.

Posted by Manisha Sahu 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Nishu Sahu 6 years, 5 months ago

Repulsive force act betwn them. As ball are bring in contact so charge get equally distribute betwn them.

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Is it true that que in board come mostly based on ncert que?

Posted by Nishu Sahu 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Hritik Kumar 6 years, 5 months ago

80percent

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Priya Dharshini ? 6 years, 5 months ago

85% true...

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For practice numerical we should focus on which more ncert or any reference for board only.

Posted by Nishu Sahu 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Riya Sinha 6 years, 5 months ago

Also try sl arora

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Priya Dharshini ? 6 years, 5 months ago

Ncert

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Distinguish between ordinary Ray and extraordinary Ray.

Posted by Isha Gurav 4 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 4 years, 3 months ago

O-Ray | Ordinary ray

• As shown, plane of polarization of o-ray is perpendicular to the plane of figure.
• It is known as ordinary ray.
• It follows Snell's law of refraction.
• The velocity of o-ray i.e. vo is c/no.

E-Ray | Extraordinary ray

• As shown, plane of polarization of o-ray is in the same plane as of figure.
• It is known as Extraordinary ray.
• It does not follow Snell's law of refraction.
• The velocity of e-ray i.e. ve is c/ne.

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Why the eletric field inside a dielectric decrease when it placed is an external electric field?

Posted by Ankit Aryan Shivan 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 5 months ago

A dielectric material gets polarized when it placed in an electric field. The field produce due to the polarization of material minimize the effect of external field. Hence, the electric field inside a dielectric decreases when it is placed in an external electric field.

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In Gauss law why we cosider enclosed charge

Posted by Simran Vaaghela 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Shatayu Ganvir 6 years, 5 months ago

*zero***

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Shatayu Ganvir 6 years, 5 months ago

For charges present outside surface.. E flux becomes zera

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when there is earthing when does electrons flow from ground to sphere and from sphere to ground?

Posted by Krutika Guru 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

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where i can get the 2020 sample paper ? please please

Posted by Abhilash Rai 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Priya Dharshini ? 6 years, 5 months ago

It will be available in mycbseguide app by october

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Kumar Vishal Behera 6 years, 5 months ago

Will be available soon by September-october

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Given a uniform electric field 2 x 103 ? N/C . Find the flux of this field through a square of 5 cm on a side whose plane is parallel to the Y-Z plane. What would be the flux through the same square if the plane makes a 60° angle with the x-axis? Try to give answer urgent

Posted by Priya Dharshini ? 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Dispersion is the splitting of light into its constituent colours.

Posted by Prabhat Yadav 6 years, 5 months ago

CBSE > Class 12 > Physics

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ANSWER

What are the formulae for electric flux?

Posted by Dev Rao 6 years, 5 months ago

CBSE > Class 12 > Physics

4 answers

Nishu Sahu 6 years, 5 months ago

Electric flux = vector E.vector ds Or. E ds cos theta. Where ds=area

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Shatayu Ganvir 6 years, 5 months ago

Ebar.jbar

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Aman Kumar 6 years, 5 months ago

Flux is denoted by fai...Therefore, ..Fai = E.A cos theta.....

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Pooja Rawat 6 years, 5 months ago

E=1×q1×q2/4π€r×r

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ANSWER

Explain construction and working of electroscope

Posted by Suraj Yadav 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is electric filed and flux

Posted by Chinki Nk 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Priya Dharshini ? 6 years, 5 months ago

Electric field is a region around a charged particle or object within which a force would be exerted on other charged particles or objects. Electric flux is the measure of flow of the electric field through a given area

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why does one can ignore quantisation of electric charge when dealing with macroscopic i.e. large scale charges

Posted by Arushi Gupta 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Pragati Gola 5 years, 5 months ago

We know that, q=ne the value of n become very large . We can't se earth give it's electrons to moon (because they are macroscopic).

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Three point charges arranged in triangle .find mutual p.E.

Posted by Rohit Rao 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

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HC verma ke numericals board exam me v aate h ?

Posted by Riya Sinha 6 years, 5 months ago

CBSE > Class 12 > Physics

2 answers

Hritik Kumar 6 years, 5 months ago

Nhi it us for iit jee

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Adarsh Deep Gupta 6 years, 5 months ago

Nhi... Only for iit

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Under the action of a given coulombic force the acceleration of an electron is 2.5×10^22m/s^2 .then the magnitude of the acceleration of a proton under the action of same force

Posted by Anshika Chaudhary 6 years, 5 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is the defination of electrostatics

Posted by Happy Vishwakarma 6 years, 5 months ago

CBSE > Class 12 > Physics

3 answers

Hritik Kumar 6 years, 5 months ago

The study of the electric charge at rest

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Yogita Ingle 6 years, 5 months ago

Electrostatic:- It is a branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges with no acceleration.

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Riya Sinha 6 years, 5 months ago

The study of specified electric charge which are in rest

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Why electric field lines donot form any closed loops??

Posted by Hardeep Singh 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Priya Dharshini ? 6 years, 5 months ago

Because electric field lines originate from positive charge and terminate at negative charge.electric field lines do not pass through the charge

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Explain the electrostatic shielding with diagram.

Posted by Udit Tomar 6 years, 5 months ago

CBSE > Class 12 > Physics

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Columb loe

Posted by Aman Yadav 6 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Nikhil Bhimra 6 years, 5 months ago

According to this law force experienced by two stationary charges is directly proportional to product of magnitude of two charges and inversly proportional to the square of distance.

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Why we cannot prepare haloarene by reaction with hydrogen halide

Posted by Apurva Damandhe 6 years, 5 months ago

CBSE > Class 12 > Physics