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

Ac current is such as electric magnet machine which convert the mechanical cell energy into electric energy Principles. Whenever a closed coil is rotated in a magnezic field in a high speed then the number of line of magnetic force continuously changef so induced electric current is produced in the coil

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Shruti Jha 6 years ago

Principle: AC generator works on the phenomenon of EMI. You can see ncert diagram where if a rectangular armature coil rotates about its axis in a uniform magnetic field, the magnetic flux linked with coil changes and an induced emf is set up in the coil. The direction of induced current is given by Fleming's right hand rule. Working: When an armature coil of N turns each of area A is placed in uniform magnetic field of strengt B making angle thita from normal to the direction of magnetic field, the magnetic flux linked with the coil id NBAcos thita. As the coil rotates about its axia with angular speed, magnetic flux changes and an induced emf develops across the end of coil. Refer ncert for diagram!

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ANSWER

Galvanometer smjaha do in detail pls

Posted by Nancy Verma 6 years ago

CBSE > Class 12 > Physics

31 answers

Shruti Jha 6 years ago

High hopes!!!

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Ritwik Choudhary 6 years ago

Don't worry.....everything will be fine

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Shruti Jha 6 years ago

Maybe. Cuz' parents have high expectations. And tbh mujhe medical me koi interest hi nahi tha but just for my parents sake i am doing this. High hopes sab accha ho.

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Ritwik Choudhary 6 years ago

Stress?? For board exams?

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Shruti Jha 6 years ago

Noipeeee. I am not feeling sleep. Thora stress hain maybe.

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Ritwik Choudhary 6 years ago

It seems like shruti you're feeling sleepy

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Shruti Jha 6 years ago

Pata nahi rey it's as if kuch to ho raha hain i am not able to recognise. How weird, nai?

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Shruti Jha 6 years ago

Boring?

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Nancy Verma 6 years ago

Kya ho rha hai shruti boring?

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Shruti Jha 6 years ago

Oh! Same Rishika. I aslo wanted Psychology but school me option tha hi nahi.

1Thank You

Shruti Jha 6 years ago

I think mujhe kuch ho raha hain!??

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Ritwik Choudhary 6 years ago

But i wanted psychology as my 5th subject.....but our schl has no option for it

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Ritwik Choudhary 6 years ago

PHYSICAL EDUCATION

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Ritwik Choudhary 6 years ago

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Nancy Verma 6 years ago

Ayaan bro kaha ho bta do apne subjects.but rishika I think subject to same hi hoga bs lesson or kuch topics hi change honge

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Ritwik Choudhary 6 years ago

Grt...??

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Shruti Jha 6 years ago

Ayaan janab Rishika ke puche gaye sawal ka jawab dijiye. She asked you about your 5th subject.

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Ritwik Choudhary 6 years ago

Nancy but i asked bout his 5th subject.....as we have PE

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Nancy Verma 6 years ago

Rishika I think vo apki ko ans de rhe

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Ritwik Choudhary 6 years ago

Hey... U didn't answer me..

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Ritwik Choudhary 6 years ago

What's ur 5th subject ....other than language and science

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???. Pragati 6 years ago

Right ???

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???. Pragati 6 years ago

Kahan se ho Ayaan

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Nancy Verma 6 years ago

Kisska different hai ayan

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Shruti Jha 6 years ago

No need to be thank, Nancy! Anytime.

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Nancy Verma 6 years ago

Thankyou all mujhe bhut confusion tha iss topic ko leker

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???. Pragati 6 years ago

Kyu Ayaan tum cbse board se nhi ho kya?

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Shruti Jha 6 years ago

Jiiii haan Ayaan! Derivations bohot puchte hain.

1Thank You

Nancy Verma 6 years ago

Actually practical time maine learn kiya tha bt clear nhi hua to soch puch lu during exam nhi aaye sayad but knowledge rkhni chaiye

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Shruti Jha 6 years ago

A galvanometer is a device use to detect current in a circuit. When a current carrying coil is placed in magnetic field it experiences torque, the magnitude which depends on the strength of current. Here the deflection torque and restoring torque is equal to each other and at equilibrium the deflection of coil is proportional to current.

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Ritwik Choudhary 6 years ago

A galvanometer is a device that is used to detect and measure the magnitude of small electric current. The current and its intensity is usually indicated by a magnetic needle’s movement.

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ANSWER

Cyclotron koi detail mai smjha do yrr smjh nhi aa rha

Posted by Nancy Verma 6 years ago

CBSE > Class 12 > Physics

6 answers

Ankit Singh 6 years ago

Sorry 10 lakh hz

2Thank You

Ankit Singh 6 years ago

Rishika .. good and also polarity of dees also changed ( oscillates) by providing a very high voltage approximately 10hz

2Thank You

Shruti Jha 6 years ago

Cyclotron is a device that accelerate heavy particles. Principle: it works on the principle which states that when an charged particle enters in a unifirm magnetic field it experiences magnetic force. Thus, follows circular motion and whenever it comes inside the gap, gets accelerated by electric field. Working: let t=0 be the time when an source produces positive charge which is attracted by dee's D1 being negatively charged. It enters in D1 with velocity V1 perpendicular to magnetic field. So it follows uniform circular motion woth radius r and appear in between gap after following semicircle. The frequency of AC source is adjusted such that the time when charged particle complete semicircle, the dee's phase gets flip. Now the particle is attracted by dee's D2 . Again it follows circular motion completing semicircle. This process is repeated in time and again till charged particle acquires desired velocity!

2Thank You

Nancy Verma 6 years ago

Thankyou so much kushal and rishika

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Ritwik Choudhary 6 years ago

A cyclotron accelerates a charged particle using a high-frequency alternating voltage which is applied between two hollow “D”-shaped sheet metal electrodes called “dees”. The dees are placed face to face with a narrow gap between them, creating a cylindrical space within them for the particles to move. Then, the particles are injected into the centre of this space. The magnetic field causes the path of the particles to bend in a circle due to the Lorentz force perpendicular to their direction of motion. THAT'S IT!?

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Kushal Prajapat 6 years ago

Cyclotron is used to accelerate particles in magnetic field and smaller particles like electron cannot be accelerate d

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ANSWER

Professor surprised his student by suspendingg freely a tiny light ball in a transparent vacuum chamber by shinning a laser beam on it which property of EM waves was he exhibiting ?

Posted by Ankit Singh 6 years ago

CBSE > Class 12 > Physics

1 answers

Avantika Tayal 6 years ago

Em waves does not require medium to travel

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ANSWER

Law of refraction of light based on wave theory

Posted by Viruthika M 6 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

A nucleus X emits one alpha particle and one beta partical if mass number of X is 180 and atomic no. is 73 what will be the atomic no. Of resultant daughter nucleus

Posted by Geetika Kumari 6 years ago

CBSE > Class 12 > Physics

1 answers

Muskaan Vig 6 years ago

Atomic no.72 and mass no.176..

2Thank You

ANSWER

Name the factor which determines frequency and intensity of light emitted by LED

Posted by Meghna Sharma 6 years ago

CBSE > Class 12 > Physics

1 answers

Rajat Barwar 6 years ago

The composition of the LED should be a factor... Bcoz the band gap decides the energy change and hence the wavelength of the light emitted... Hope it may help you...

1Thank You

ANSWER

Why are Si and GaAs are preferred materials for solar cells?

Posted by Meghna Sharma 6 years ago

CBSE > Class 12 > Physics

1 answers

Ridima Nehra 6 years ago

Si and Ga have low threshold electron potential hence they are preferred in solar cell. these materials are preffered because of their lower value of energy gap. SO that they can be activated using solar radiation.

1Thank You

ANSWER

What is the effect on interference if screen is moved away

Posted by Rakesh Yadav 6 years ago

CBSE > Class 12 > Physics

2 answers

Muskaan Vig 6 years ago

Sorry intensity of bright fringes will decrease.......and fringe width =Dlamda/d will increase....

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Muskaan Vig 6 years ago

Intensity will decrease of fringes will decrease..

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ANSWER

What happens when dielectric slab is replaced by conducting slab in parallel plate capacitor keeping the thikness same

Posted by Sangita Maheshwari 6 years ago

CBSE > Class 12 > Physics

3 answers

Muskaan Vig 6 years ago

Electric field become 0 inside conducting slab due to which capacitance increases by factor of (d/d-t) where d is distance between parallel plates and t is thickness of conducting slab...

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Vaishnavi Kalvakuntla 6 years ago

Increases k times

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Killer Xmarty 6 years ago

Then fat jayega

1Thank You

ANSWER

Physcis mei 20 marks ke objective aa rhe h ....kese prepare kare unko....plzz tell me

Posted by Falguni Soni 6 years ago

CBSE > Class 12 > Physics

1 answers

Ridima Nehra 6 years ago

Read Ncert Thoroughly and try to make 1 mark ques while u read U will not only get objectives but also fill ups and 1 word or 1 line answers All the Best ! ??

3Thank You

ANSWER

What do u mean by rest mass of photon?

Posted by Falguni Soni 6 years ago

CBSE > Class 12 > Physics

2 answers

Falguni Soni 6 years ago

Thank u harishta

0Thank You

Ridima Nehra 6 years ago

The rest mass is the mass of a particle (in our case the photon) as measured by an observer who sees the particle still and with zero speed. In other words, the particle is at rest as far as this observer is concerned. Thus comes the term REST mass.

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ANSWER

Posted by Abhilasha Sauliyal 6 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Can we helpfull in board exams by solving last 5 years papers

Posted by Sushant Kumar 6 years ago

CBSE > Class 12 > Physics

2 answers

Anubhav Sharma 6 years ago

Yes

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Devyani Malvi 6 years ago

Yes

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ANSWER

Jee kee tyare kon kon kar rha ha

Posted by Dhruv Rajput 6 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

How to proof Ic=Id

Posted by Ayan Ali 6 years ago

CBSE > Class 12 > Physics

4 answers

Muskaan Vig 6 years ago

Ic=dq/dt..........................and.....Id=ε°dØ/dt...............now,Ø=q/ε°..(acc. to gauss law..)...put this value in Id.....we get......ε°d(q/ε°)÷dt=dq/dt....which is equal to Id ,hence Id =Ic..........

1Thank You

Killer Xmarty 6 years ago

Bang ang krlo

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Navneet . 6 years ago

???? alle waah ...

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Shruti Jha 6 years ago

Ayaan got someone?

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ANSWER

Which changes affect balance point of meterbridge

Posted by Akanksha Dhawaliker 6 years ago

CBSE > Class 12 > Physics

1 answers

Vaishnavi Kalvakuntla 6 years ago

Change in resistance

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ANSWER

Is human eye is included in syllabus of physics (ray optics) class 12 2020???

Posted by Sweta Sinha 6 years ago

CBSE > Class 12 > Physics

7 answers

Killer Xmarty 6 years ago

Yssssss

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Dhruv Rajput 6 years ago

Yes bro only in yor syllabus?

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Rituporna Gohain 6 years ago

0Thank You

Ayan Ali 6 years ago

1Thank You

Gaurav Rawat 6 years ago

1Thank You

Muskaan Vig 6 years ago

No..this topic is excluded from syllabus this year....

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Shruti Jha 6 years ago

Yes.

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ANSWER

Shruti pdha do?????

Posted by Rameez Khan 6 years ago

CBSE > Class 12 > Physics

15 answers

Killer Xmarty 6 years ago

Love

1Thank You

Shruti Jha 6 years ago

Kyaaa hua?

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Killer Xmarty 6 years ago

0Thank You

Shruti Jha 6 years ago

Rameez??

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Killer Xmarty 6 years ago

Plz

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Killer Xmarty 6 years ago

Loove u

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Shruti Jha 6 years ago

Kya hmm? What happened to you ?

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Killer Xmarty 6 years ago

Hmm jaan

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Shruti Jha 6 years ago

Kyaaa?

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Shruti Jha 6 years ago

Main kese padha sakti hu???

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Rameez Khan 6 years ago

I love u

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Shruti Jha 6 years ago

Main kese padha sakti hu?

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Rameez Khan 6 years ago

Ky kr ri ho

1Thank You

Rameez Khan 6 years ago

Kuch bhi

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Shruti Jha 6 years ago

Main kya padhau?

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ANSWER

Is van de graff generator in syllabus

Posted by Pk Rabari 6 years ago

CBSE > Class 12 > Physics

4 answers

Priya Aggarwal 6 years ago

1Thank You

Rameez Khan 6 years ago

Nooo

1Thank You

Shruti Jha 6 years ago

Noo

1Thank You

Tamanna Sharma 6 years ago

1Thank You

ANSWER

Btw any momos lover here? Ps. Just to fresh y'all mind i have asked.

Posted by Shruti Jha 6 years ago

CBSE > Class 12 > Physics

34 answers

Killer Xmarty 6 years ago

Tmse jn

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Shruti Jha 6 years ago

???

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Shruti Jha 6 years ago

Hahah sahi hain pragati!

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Killer Xmarty 6 years ago

Tmse

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Navneet . 6 years ago

Yeah my nickname ? kya kare sab avneet se ladka samjhne lg rhe??? iss batch wale bache

1Thank You

Shruti Jha 6 years ago

Kis se hua hain rameez?

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Shruti Jha 6 years ago

Means Pragati is only Avneet?

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Killer Xmarty 6 years ago

Pyaar

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Shruti Jha 6 years ago

Rameez kya hua hain tumko?

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Shruti Jha 6 years ago

Okay okay! I remember now. ??

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Navneet . 6 years ago

Specially known by - hookah girl ❤️ Cuteness overload❤️ Avneet ❤️ My usernames????

1Thank You

Killer Xmarty 6 years ago

Wht

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Navneet . 6 years ago

U remember me or not??

1Thank You

Shruti Jha 6 years ago

Karti thi

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Navneet . 6 years ago

Kyu tum 10th me app nhi use krti thi ??

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Shruti Jha 6 years ago

Pragati whom you remember ? Me?

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Navneet . 6 years ago

Yeah I remember u from 10th grade ?

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Shruti Jha 6 years ago

Whu can't they reply Rameez? I have asked this to everyone.

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Shruti Jha 6 years ago

Yes Avneet!

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Rameez Khan 6 years ago

Shruti yrr jn

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Rameez Khan 6 years ago

Yrr but why they r rplying...

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Shruti Jha 6 years ago

Rameez how many time i have to say you don't abuse anyone! Please.

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Navneet . 6 years ago

Shruti u r old user n

1Thank You

Shruti Jha 6 years ago

We are also same, Avneet!?

1Thank You

Navneet . 6 years ago

Ooo hello abuse kise kr rha

0Thank You

Rameez Khan 6 years ago

Bhk saale

0Thank You

Navneet . 6 years ago

Yess ??

1Thank You

Rameez Khan 6 years ago

Babes

1Thank You

Rameez Khan 6 years ago

U also

1Thank You

Rameez Khan 6 years ago

Yup

1Thank You

Shruti Jha 6 years ago

Ahaa! ?

0Thank You

Shruti Jha 6 years ago

Ahaa! We are same.

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Rameez Khan 6 years ago

????

2Thank You

Rameez Khan 6 years ago

Yesss

1Thank You

ANSWER

Arre out of u guys who r planning for foreign??

Posted by Meghna Sharma 6 years ago

CBSE > Class 12 > Physics

1 answers

Rameez Khan 6 years ago

Meeeeee

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ANSWER

??????

Posted by Shruti Jha 6 years ago

CBSE > Class 12 > Physics

29 answers

Killer Xmarty 6 years ago

0Thank You

Shruti Jha 6 years ago

Okay!

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Killer Xmarty 6 years ago

Yes

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Shruti Jha 6 years ago

Areeh are you ok?

0Thank You

Killer Xmarty 6 years ago

Plz

0Thank You

Shruti Jha 6 years ago

Main kya padhau?

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Shruti Jha 6 years ago

Padh rahi hu filhal!

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Rameez Khan 6 years ago

Acha hme pdha dijiye jaan

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Shruti Jha 6 years ago

Padh rahi hu filhal

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Rameez Khan 6 years ago

Kya kr ri ho babes

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Shruti Jha 6 years ago

Kya batau?

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Rameez Khan 6 years ago

Okk...aur btaye

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Shruti Jha 6 years ago

I am also good!

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Rameez Khan 6 years ago

Fine...aap btai

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Shruti Jha 6 years ago

Hello Rameez! Kuch nahi hua h. How's you?

0Thank You

Rameez Khan 6 years ago

Kya hua

0Thank You

Shruti Jha 6 years ago

Haha Cool than!

1Thank You

Shruti Jha 6 years ago

I am too formal with everyone!

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Shruti Jha 6 years ago

It's not about Sorry, Meghna! Chillax.

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Shruti Jha 6 years ago

No it's like if i don't like anything than i don't like. That's it! I can't take it.

0Thank You

Meghna Sharma 6 years ago

Sry if u take it on urs. Am formal with u.

0Thank You

Meghna Sharma 6 years ago

Are shruti meine aapko nhi bola

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Shruti Jha 6 years ago

Seriouly, Meghna??? Aunty jii? Who does that? I already have n numbers of nicknames not anymore.

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Meghna Sharma 6 years ago

Abhi board ke exams bhi dene kaise handle kroge ayaan

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Meghna Sharma 6 years ago

Aunty ji itni tension mat lo

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Shruti Jha 6 years ago

Kuch nahi! Bas on the way to depression.? like depression bula raha h and i am thinking shall i go or not!?

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Meghna Sharma 6 years ago

Kachu bat na h

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Meghna Sharma 6 years ago

Shruti

0Thank You

Meghna Sharma 6 years ago

Sab saras che

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ANSWER

Define eddy current and give 2 of its application

Posted by Swagata Paul 6 years ago

CBSE > Class 12 > Physics

1 answers

Muskaan Vig 6 years ago

Eddy currents are circulating currents that come into existence whenever magnetic flux changes from metallic masses.....application ..in induction furnance and inductothermy..

1Thank You

ANSWER

What is Q-factor of circuit?

Posted by Ankit Singh 6 years ago

CBSE > Class 12 > Physics

1 answers

Muskaan Vig 6 years ago

It ratio of voltage across inductor or capacitor to applied voltage in a LCR circuit...it tells us sharpness of resonance i.e. greater Q value ,Less the resistance,greater resonance ,greater current through LCR circuit..

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ANSWER

suggest a suitable method invert an image 1)without change in size 2)without change in size and without deviation from its direction of view Explain how the same is achieved.

Posted by Aman Saharan 6 years ago

CBSE > Class 12 > Physics