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

Metallic strips have negligible resistance and need not to be counted in the length l1, of the null point of potentiometer. That’s why the thick metallic strips are used in potentiometer. It is for the convenience of experimenter as he measures only their lengths along the straight segments each of lengths 1 m. This measurements is done with the help of a centimetre scale or metre scale and leads to the accurate measurements.

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ANSWER

Predict the direction of induced current

Posted by Shruti Sharma 6 years, 6 months ago

CBSE > Class 12 > Physics

3 answers

Riti Bansal 6 years, 6 months ago

Use right thumb rule

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Nishu Sahu 6 years, 6 months ago

By Fleming right hand rule

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Sukhjinder Kaur 6 years, 6 months ago

By right hand thumb rule

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ANSWER

Define the 1 ampere

Posted by Piyush Pradhan 6 years, 6 months ago

CBSE > Class 12 > Physics

2 answers

Jk Verma 6 years, 6 months ago

One ampere is that value of that steady current which, when maintained in each of the two very long,straight,parallel conductors of negligible cross-section,and placed one metre apart in vacuum ,would produce on each of these conductors a force equal to 2×10^-7 newtons per metre of length.

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Vanshika Dhawan 6 years, 6 months ago

One ampere of current represents one coulomb of electrical charge (6.24 x 1018 charge carriers) moving past a specific point in one second.

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ANSWER

Ncert is enough or we have to study side books like arihant all in one because board pattern is change

Posted by Yakuza Shimatoro 6 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Pragati Saini 6 years, 6 months ago

Actually we have to study arihant books for boards these books are very important to boards point of view

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ANSWER

if voltage in ac circuit is 220√2sin(314t-q)calculate peak and rms voltage average voltage over half cycle frequency of ac

Posted by Sangeeta Guglani 6 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 6 years, 6 months ago

For a.c. voltage
{tex}V = {V_0}\;\sin \left( {\omega t - \phi } \right){/tex}
The peak value
{tex}{V_0} = 220\sqrt 2 = 311V{/tex}
The rms value of voltage
{tex}{V_{rms}} = \frac{{{V_0}}}{{\sqrt 2 }};\;{V_{rms}} = 220V{/tex}
Average voltage in full cycle is zero. Average voltage in half cycle is
{tex}{V_{av}} = \frac{2}{\pi }{V_0} = \frac{2}{\pi } \times 311 = 198.17V{/tex} = 198.17 V
As {tex}\omega = 2\pi f,\;2\pi f = 314{/tex}
i.e. {tex}f = \frac{{314}}{{2 \times \pi }} = 50\;Hz{/tex} = 50 Hz

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ANSWER

What do you mean by "Motional EMF"?

Posted by Rahul Kumar Yadav 6 years, 6 months ago

CBSE > Class 12 > Physics

3 answers

Riti Bansal 6 years, 6 months ago

Is induced emf which always oppose change in magnetic field

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Khuskaran Sidhu 6 years, 6 months ago

The induced emf which always opposes the change in magnetic flux is called motional emf. €=- Blv

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Shubham Kumar Gupta 6 years, 6 months ago

Ooooooooo....

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ANSWER

How to clear concepts on physics?

Posted by Ramkrishna Uniyal 6 years, 6 months ago

CBSE > Class 12 > Physics

3 answers

Supriya Kumari 6 years, 6 months ago

You need to labour hard on only one question,that after your concept will clear by your smart labour.

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Pragati Saini 6 years, 6 months ago

Yes u are right ?

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Avi Bhatnagar 6 years, 6 months ago

solve the question as much as you can this may clear your all concepts of physics.....I'm telling it with my experiece

1Thank You

ANSWER

A proton and an alpha particle describe circular paths of equal radius in a uniform magnetic field. What is the ratio of their kinetic energy?

Posted by Mayank Nigam 6 years, 6 months ago

CBSE > Class 12 > Physics

2 answers

Pragati Saini 6 years, 6 months ago

I:2 is the correct answer

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Gujjar Nishant 6 years, 6 months ago

The ratio of there kinetic energy is 1by 4

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ANSWER

derivation of ac gernator

Posted by Reigns Media 6 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Khuskaran Sidhu 6 years, 6 months ago

Its too long Either search on Google or look at NCERT (or any other) book

2Thank You

ANSWER

Ac source connect with only resistor

Posted by Anshu Solanki 6 years, 6 months ago

CBSE > Class 12 > Physics

2 answers

Riti Bansal 6 years, 6 months ago

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Vanshika Dhawan 6 years, 6 months ago

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What is the average value of a.c.over a cycle??

Posted by Gurmanjeet Khera 6 years, 6 months ago

CBSE > Class 12 > Physics

3 answers

Aman Kumar 6 years, 6 months ago

The avg.value is always defined for half cycle

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Gujjar Nishant 6 years, 6 months ago

Ues it is zero

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Anshu Solanki 6 years, 6 months ago

I av=0

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ANSWER

Chapter 1 exercise solution

Posted by Anshu Solanki 6 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 6 years, 6 months ago

You can check NCERT Solutions here : https://mycbseguide.com/ncert-solutions.html

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ANSWER

Current I in a circuit varies with the time t as per as relation given below i= 3k + 2k' × t . Find the constant current which said the charge equivalent to the time travel t=0 to t= 4sec.take constant k and k' as unity.

Posted by Arman Ahmed 6 years, 6 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

define decay constabt

Posted by Sonu Thakur 6 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 6 years, 6 months ago

Decay constant of a radioactive element is the reciprocal of the time during which the number of atoms left in the sample reduces to {tex}\frac{1}{e}{/tex} times the original number of atoms in the sample.

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ANSWER

Is Current flow in Na (sodium) or not

Posted by Ɽøⱨł₮ ₲Ʉ₱₮₳ 6 years, 6 months ago

CBSE > Class 12 > Physics

6 answers

Nishu Goyal 6 years, 6 months ago

Yes it will

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Ɽøⱨł₮ ₲Ʉ₱₮₳ 6 years, 6 months ago

All

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Ɽøⱨł₮ ₲Ʉ₱₮₳ 6 years, 6 months ago

Tnx

2Thank You

Nishu Sahu 6 years, 6 months ago

In molten and aqueous state current flows through Na but in solid state does not

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Amol Gùpta 6 years, 6 months ago

It need ionic form for the flow of electricity

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Gurman Kaur 6 years, 6 months ago

If it is in form of ion then current will flow

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ANSWER

What are the limitations of rutherford atom

Posted by Monika Dangi 6 years, 6 months ago

CBSE > Class 12 > Physics

3 answers

Monika Dangi 6 years, 6 months ago

More explanation that i have already read if you can help give me more guidance

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Nishu Goyal 6 years, 6 months ago

It was not able to explain spectrum of light . It was not able to explain stability of electron in atom .

1Thank You

Gaurav Seth 6 years, 6 months ago

According to Rutherford model, there is a positively charged centre in an atom called the nucleus and the electron present in nucleus revolve aroun it, in well- defined orbits. But, since an electron is charged particle. Thus, while revolving around the nucleus it lose energy and finally fall into the nucleus. If this were so, the atom should be highly unstable and hence matter would not exist in the form that we know.

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Oh god this NCERT exemplar has questions above the concept of NCERT l am not getting them....??

Posted by ꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

CBSE > Class 12 > Physics

43 answers

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

1Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Tution toh yrr mera 10th m hi tha vo b sirf maths ka...baaki kbhi tution nhii

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Me too same here, but mujhhe koi problem nahi aati kyunki maine aaj tak kabhi tution nahi li...apne aap hi manage kiya hai...isliye aadat hai....baaki teachers hai....

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Srishti Choudhary ✍⏳ 6 years, 6 months ago

Kuchh ni hua....yrr koi tution ni h...sb apne aap manage krna pdta h....

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꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Online kam aati ho baat kam karti ho hua kya hai

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꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Haa

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꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Konse¿??

0Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Mere te puche hi na

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Arrey school ka kya karna mujhe tere kitne hue....

1Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Chemistry m 7 complete ho gye...or ch &6 is going on

1Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Physics m 8th is going on in school

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Kitne chapters hue chemistry aur physics mai

1Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Hmm...shi keh ri

2Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Haa, all are right...par Darshana ka yeh kya concept hai samaj nahi aaya ?

1Thank You

Amol Gùpta 6 years, 6 months ago

It was too good shrishti hm jaise logo k liye hi bni thi ye movies ??? shayad

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Taare jameen par ???

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Nice one sristhi ???

2Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Confusion hi confusion h solution ka kuchh pta nhi...jb solution mila toh question kya tha pta nhi....

2Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Hmm...sbki yhi haalat h...sb preshaan h...

1Thank You

Amol Gùpta 6 years, 6 months ago

Shrishti shkl ka to pta nhi pr taare zameen pr waale ishaan jaise haalat ho jaate h kbhi kbhi ???

1Thank You

Amol Gùpta 6 years, 6 months ago

Sahi bol rhi ho mamta

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Mujje bhi kuch aisa hi lagta hai Srishti....kya kare?

1Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Ishu sabki problem hai...tum akeli nahi ho but 12th hai manage karna padta hai.....par concept clearance honi chahiye

0Thank You

Amol Gùpta 6 years, 6 months ago

Yaha to sb log ncert exemplar solve kr rhe h and mai ncert me hi confused hu don't know what to do ??

1Thank You

Srishti Choudhary ✍⏳ 6 years, 6 months ago

Books m kisi ki shkl nhi dikhti....ab toh aisa lgta jaise board dene k liye centre pr bethe..h...or kuchh nhi aata...

2Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

1Thank You

Ďãřşháñăã Yadav ? ? ? 6 years, 6 months ago

???

1Thank You

Řøhăň Řąjpůť ✌️✊ 6 years, 6 months ago

aur behtar hoga... focus on study... exams aa re hai.. ? ? Verna iss baar jesa rona na ho Jaye.. iseliye prepare ker lo... faltu tym waste Kerne se accha hoga. @Darshana yadav. ??

3Thank You

Řøhăň Řąjpůť ✌️✊ 6 years, 6 months ago

Haan bhai.. koi ni.

0Thank You

Ďãřşháñăã Yadav ? ? ? 6 years, 6 months ago

dekho aesa bura majak nhi kerte. agar tumhari shkl dekhti usmein toh NCERT uss book ko publish he nhi hone deti. ?? soch smjh kar bola kero. ? ? ? subha subha aesa makak logo ki health par adverse effect dal skta hai. ?

2Thank You

Řøhăň Řąjpůť ✌️✊ 6 years, 6 months ago

kebhi seedhe question ka seedha answer nhi de milta tumse. ? ? .. vese cover mein meri shkl nhi dekhegi... so cover ko dekhna chor do... book ka content dekho. ? ? ??

2Thank You

Ďãřşháñăã Yadav ? ? ? 6 years, 6 months ago

na Rohan solve Kerne ke liye thodi layi hoon bus din mein 2 baar uske cover ki shkl dekhti hoon. ??

1Thank You

Ďãřşháñăã Yadav ? ? ? 6 years, 6 months ago

welcome ?

1Thank You

Řøhăň Řąjpůť ✌️✊ 6 years, 6 months ago

aesa toh kuch khaas suggest kiya nhi usnay. ? ?

0Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Thanks darshu

1Thank You

Řøhăň Řąjpůť ✌️✊ 6 years, 6 months ago

it means u are solving this darshu am I r8 na. ???

1Thank You

Ďãřşháñăã Yadav ? ? ? 6 years, 6 months ago

look only some questions of ncert exemplar are from examination point of view... so, it's mandatory to clear all ur concept of basic as well as some higher one.

4Thank You

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

Ya u are right.. that's why I am asking that...

1Thank You

Pragati Saini 6 years, 6 months ago

But its important for 20 objective questions asked in cbse board

1Thank You

Amol Gùpta 6 years, 6 months ago

Koi mujhe bta de ??

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꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 6 months ago

What should I do, how to do them...