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

Gauss's Theorem: According to Gauss's theorem total number of electric lines of force passing normally through a closed surface of ray shape in an electric field(i.e., total electric flux) is equal to 1/εo times the total charge present within that surface. i.e., ΦE=εoq where, εo= permitivity if free space, q in vaccum. Derivation of Gauss's Theorem: Let +q charge is placed at a point O and a point P lies at distance r from the point O. Imagine a sphere of radius r and centre O. Thus, point P lies on the surface of the sphere. Now, the surface of the sphere will be have as Gaussian surface. Therefore, the intensity of electric field on the surface at all the points will be equal in magnitude and will be directed radially outward. ∴ The electric flux passing through the spherical surface. Φ=E.S.cos0o Where S is surface area i.e., S=4πr2= Surface area of sphere ∴ΦE=E.S. or ΦE=4πr2E .........(i) But, by Gauss, theorem, we have ΦE=εoq .....(ii) Hence, from equation (i) and (ii), we get E4πr2=εoq or E=4πεor2q Now, imagines a charge qo placed at point P. ∴Force on qo, F=qoE F=4πεor2qoq F=4πεo1⋅r2qoq. Which is Coulomb's inverse square law.

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state and explain coulomb's law.then derive Newton's 3rd law of motion using coulomb's law

Posted by Priyanka Sahoo 5 years, 2 months ago

CBSE > Class 12 > Physics

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There is an electric dipole having +- 4maceo coloumb which is separated by 3m. Find the potential at any point which is at a distance 6m away from the midpoint of the dipole. The dipole is aligned at 60° with the direction of the point p

Posted by Roshni Tamang 5 years, 2 months ago

CBSE > Class 12 > Physics

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There is an electric dipole having charges +- 2macro coloum which is separated by 4m. Find the potential at points At an equatorial point which is 2m away from the midpoint of the dipole At am axial point which is 2m away from the midpoint of the dipole

Posted by Roshni Tamang 5 years, 2 months ago

CBSE > Class 12 > Physics

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plz help me in question 1.3 of physics

Posted by Mahendra Rathor 5 years, 2 months ago

CBSE > Class 12 > Physics

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Half yearly exam kab start hogi ??... & physics ka syllabus kya hoga is bar exam me.?

Posted by Shraddha ✨✰✰ 5 years, 2 months ago

CBSE > Class 12 > Physics

5 answers

Shraddha ✨✰✰ 5 years, 2 months ago

I am from gujarat . & my scl name is JNV.B.K.→JAVAHAR NAVODAYA VIDHYALAYA BANASKANTHA.

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Tanya ?? 5 years, 2 months ago

Shraddha from where you are??? And what's your scl name...

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Shraddha ✨✰✰ 5 years, 2 months ago

Hamara to aaj hi timetable. Mila hai . 5th october se start hogi exams . & tq for answering my question.

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Tanya ?? 5 years, 2 months ago

Mere bhi ho gye...bs ek rehta h vo bhi kl ka h

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Mahendra Rathor 5 years, 2 months ago

hamare to ho gaye online

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phasor diagram numerical

Posted by Jashanpreet Kaur 5 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Himanshu Jaglan 5 years, 2 months ago

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Can a get a derviations in magnetism and matter

Posted by Dharavath Mamatha 5 years, 2 months ago

CBSE > Class 12 > Physics

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Uses of magnetic elements

Posted by Simran Rathore 5 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 5 years, 2 months ago

Magnets are used inside TVs, Sound speakers and radios. The small coil of wire and a magnet inside a speaker transforms the electronic signal to sound vibrations.

Magnets are used inside a generator to transform mechanical energy to electrical energy where there are other kinds of motors which use magnets to change electrical energy to mechanical energy.

Electrically charged magnets can help cranes to move large metal pieces.

Magnets are used in filtering machines which separates metallic ores from crushed rocks.

It is also used in food processing industries for separating small metallic pieces from grains etc.

Magnets are used in MRI machines which are used to create an image of the bone structure, organs, and tissues. Even magnets are used to cure cancer.

At home, you use magnets when you stick a paper on the refrigerator in order to remember something. Attaching a magnetic bottle opener to the fridge can come in handy.

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Spectrum of electromagnetic waves?

Posted by Santosh Pratap 5 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 5 years, 2 months ago

Electromagnetic Spectrum The systematic sequential distribution of electromagnetic waves in ascending or descending order of frequency or wavelength is known as electromagnetic spectrum. The range varies from 10^-12 m, to 10⁴ m, i.e. from γ-rays to radio waves.

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give any two points of difference between Biot-savart law and Ampere circuital law.

Posted by Jackson Mairembam 5 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 5 years, 2 months ago

Biot-Savart's law
1. This law is based on the principle of magnetism.
2. This law is valid for asymmetrical current distribution.
3. This law is the differential form of magnetic field induction B^→ or magnetising force H^→.
Ampere's circuital law
1. This law is based on the principle of electromagnetism.
2. This law is valid for symmetrical current distribution.
3. This law is the integral form of
B^→ or H^→.

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two charges of magnitude -2q and +q are located at points (a,0) and (4a,0) respectively what is the electric flux due to these charges through a sphere of radius 3a with its centre at the origin

Posted by Anisha Joy 5 years, 2 months ago

CBSE > Class 12 > Physics

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Is deflection of a beam in an electric or magnetic field a convencing proof of its particle nature

Posted by Shweta Kumari 5 years, 2 months ago

CBSE > Class 12 > Physics

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Is MTG 10 year enough for boards class 12???

Posted by Samiksha Bhardwaj 5 years, 2 months ago

CBSE > Class 12 > Physics

3 answers

Anita Bishnoi 5 years, 2 months ago

NCERT is bhagawatgeeta ...........u can score 90+ only by reading NCERT.

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Diya Bolia 5 years, 2 months ago

This book is only for NEET preparation exam

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Diya Bolia 5 years, 2 months ago

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To set a common base transistor circuit and to study input and out put characterstics

Posted by Jivesh Tiwari 5 years, 2 months ago

CBSE > Class 12 > Physics

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Derivation of Lorentz force....if any body can...??

Posted by Devansh Savant 5 years, 2 months ago

CBSE > Class 12 > Physics

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What is the application of transformer?

Posted by Anne Paul 5 years, 2 months ago

CBSE > Class 12 > Physics

2 answers

Anne Paul 5 years, 2 months ago

Thanks dear?

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Meghna Thapar 5 years, 2 months ago

<div id="bcenter"> <div> </div> </div> <div> <div id="center_col"> <div id="taw"> <div> </div> <div> <div> </div> </div> <div id="tvcap"> </div> </div> <div id="res" role="main"> <div id="topstuff"> </div> <div id="search"> <div data-ved="2ahUKEwihoM73yIjsAhWqwTgGHTAnCugQGnoECBYQKA"> </div> </div> </div> </div> </div> <div data-hveid="CBQQAA" data-ved="2ahUKEwihoM73yIjsAhWqwTgGHTAnCugQjDYoAHoECBQQAA"> <div> <div> <div> </div> </div> </div> </div> <div data-md="32"> <div data-hveid="CBQQAg" id="media_result_group"> <div> <div data-count="1" data-hveid="CA4QAA" jsmodel="gpo5Gf"> <div> <div jsaction="PdWSXe:h5M12e;rcuQ6b:npT2md" jscontroller="IkchZc" jsdata="X2sNs;;Ab860w" jsmodel=""> <div data-h="130" data-nr="1"> <div data-attrid="image" data-docid="RIqv1JkxhNj3tM" data-lpage="https://www.electricaltechnology.org/2012/02/uses-and-application-of-transformer.html" data-ved="2ahUKEwihoM73yIjsAhWqwTgGHTAnCugQzkwoAHoECA4QAg" jsaction="rcuQ6b:npT2md;h5M12e" jscontroller="E2Spzb" jsdata="XZxcdf;RIqv1JkxhNj3tM;Ab8600" jsname="dTDiAc"><a data-ved="2ahUKEwihoM73yIjsAhWqwTgGHTAnCugQ9QF6BAgOEAM" href="https://www.google.com/search?q=What+is+the+application+of+transformer?&sxsrf=ALeKk00WMIobsAOgBJvtr1vT0h8C43hZGQ:1601183386150&tbm=isch&source=iu&ictx=1&fir=RIqv1JkxhNj3tM%252CqfxiXP_UdBFBZM%252C_&vet=1&usg=AI4_-kTfKHV4pKHCyU3R9-DlzMI8XWCO_A&sa=X&ved=2ahUKEwihoM73yIjsAhWqwTgGHTAnCugQ9QF6BAgOEAM#imgrc=RIqv1JkxhNj3tM"><g-img> <div> </div> </g-img></a></div> </div> </div> </div> </div> </div> </div> </div> <div data-md="61"> <div aria-level="3" data-attrid="wa:/description" data-hveid="CBQQAw" role="heading">The main application of Transformer is to Step up ( Increase) or Step down (Decrease) the level of Voltage. in other words, Increase or decries the level of Current, while Power must be same.</div> <div aria-level="3" data-attrid="wa:/description" data-hveid="CBQQAw" role="heading">Transformers are commonly present in circuit breakers, where they utilize a switch to automatically interrupt the flow of electricity and to prevent damage that can occur as a result of high voltage. The concept of battery charging is fuelled by the functioning of generators.</div> </div>

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Hi frd. As board is near I am forgetting to study plz help me???

Posted by Arsh Sandhi 5 years, 2 months ago

CBSE > Class 12 > Physics

2 answers

Siddhi Singh 5 years, 2 months ago

But how

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Ritik Sahu 5 years, 2 months ago

Time table bana ke padai Karo

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How learn too many expressions of physics ?

Posted by Archita Vashisht 5 years, 2 months ago

CBSE > Class 12 > Physics

4 answers

Archita Vashisht 5 years ago

Thank you

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Ayushi Kurmi 5 years, 2 months ago

Write all expressions on a sheet or notebook and at night just go through them

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Ayush Sandhu 5 years, 2 months ago

Do you use Instagram, I can tell you there..

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Deep Singh 5 years, 2 months ago

Write all formulas in a sheet chapterwise

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Hi frd. As board is near I am forgetting to study plz help me???

Posted by Siddhi Singh 5 years, 2 months ago

CBSE > Class 12 > Physics

4 answers

Siddhi Singh 5 years, 2 months ago

Can u tell how u all r studying

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Siddhi Singh 5 years, 2 months ago

Thanx yaar

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Sanjana Dua?????❣️ 5 years, 2 months ago

Hlo dud . Not not to become sad . I will help u in ur studies .if u need than just only msg on my I'd I help u . But u can do ur studies with full of concentration nd don't lose the hope So I wishes u a very good luck for ur preparations Good bye ??

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Mishti ???? 5 years, 2 months ago

Take some memory booster powder or almonds.... & Also do meditation I help u to learn long term N try to study new things at 4:00 to 12:00 at morning.... Nd daily revise whatever u study at night.. It may surely help u .. Regards..??

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Is ncert book is sufficient for cbse12

Posted by Komal Rao 5 years, 2 months ago

CBSE > Class 12 > Physics