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, 1 month 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!

2Thank You

ANSWER

Galvanometer smjaha do in detail pls

Posted by Nancy Verma 6 years, 1 month ago

CBSE > Class 12 > Physics

31 answers

Shruti Jha 6 years, 1 month ago

High hopes!!!

0Thank You

Ritwik Choudhary 6 years, 1 month ago

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

1Thank You

Shruti Jha 6 years, 1 month 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.

0Thank You

Ritwik Choudhary 6 years, 1 month ago

Stress?? For board exams?

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Shruti Jha 6 years, 1 month ago

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

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Ritwik Choudhary 6 years, 1 month ago

It seems like shruti you're feeling sleepy

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Shruti Jha 6 years, 1 month 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, 1 month ago

Boring?

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Nancy Verma 6 years, 1 month ago

Kya ho rha hai shruti boring?

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Shruti Jha 6 years, 1 month ago

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

1Thank You

Shruti Jha 6 years, 1 month ago

I think mujhe kuch ho raha hain!??

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Ritwik Choudhary 6 years, 1 month ago

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

0Thank You

Ritwik Choudhary 6 years, 1 month ago

PHYSICAL EDUCATION

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Ritwik Choudhary 6 years, 1 month ago

0Thank You

Nancy Verma 6 years, 1 month 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, 1 month ago

Grt...??

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Shruti Jha 6 years, 1 month ago

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

1Thank You

Ritwik Choudhary 6 years, 1 month ago

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

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Nancy Verma 6 years, 1 month ago

Rishika I think vo apki ko ans de rhe

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Ritwik Choudhary 6 years, 1 month ago

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

0Thank You

Ritwik Choudhary 6 years, 1 month ago

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

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???. Pragati 6 years, 1 month ago

Right ???

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???. Pragati 6 years, 1 month ago

Kahan se ho Ayaan

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Nancy Verma 6 years, 1 month ago

Kisska different hai ayan

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Shruti Jha 6 years, 1 month ago

No need to be thank, Nancy! Anytime.

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Nancy Verma 6 years, 1 month ago

Thankyou all mujhe bhut confusion tha iss topic ko leker

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???. Pragati 6 years, 1 month ago

Kyu Ayaan tum cbse board se nhi ho kya?

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Shruti Jha 6 years, 1 month ago

Jiiii haan Ayaan! Derivations bohot puchte hain.

1Thank You

Nancy Verma 6 years, 1 month 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, 1 month 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.

1Thank You

Ritwik Choudhary 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

6 answers

Ankit Singh 6 years, 1 month ago

Sorry 10 lakh hz

2Thank You

Ankit Singh 6 years, 1 month 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, 1 month 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, 1 month ago

Thankyou so much kushal and rishika

1Thank You

Ritwik Choudhary 6 years, 1 month 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!?

0Thank You

Kushal Prajapat 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

1 answers

Avantika Tayal 6 years, 1 month ago

Em waves does not require medium to travel

1Thank You

ANSWER

Law of refraction of light based on wave theory

Posted by Viruthika M 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

1 answers

Muskaan Vig 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

1 answers

Rajat Barwar 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

1 answers

Ridima Nehra 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

2 answers

Muskaan Vig 6 years, 1 month ago

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

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Muskaan Vig 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

3 answers

Muskaan Vig 6 years, 1 month 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, 1 month ago

Increases k times

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Killer Xmarty 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

1 answers

Ridima Nehra 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

2 answers

Falguni Soni 6 years, 1 month ago

Thank u harishta

0Thank You

Ridima Nehra 6 years, 1 month 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, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

2 answers

Anubhav Sharma 6 years, 1 month ago

Yes

0Thank You

Devyani Malvi 6 years, 1 month ago

Yes

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ANSWER

Jee kee tyare kon kon kar rha ha

Posted by Dhruv Rajput 6 years, 1 month ago

CBSE > Class 12 > Physics

0 answers

ANSWER

How to proof Ic=Id

Posted by Ayan Ali 6 years, 1 month ago

CBSE > Class 12 > Physics

4 answers

Muskaan Vig 6 years, 1 month 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, 1 month ago

Bang ang krlo

0Thank You

Navneet . 6 years, 1 month ago

???? alle waah ...

0Thank You

Shruti Jha 6 years, 1 month ago

Ayaan got someone?

0Thank You

ANSWER

Which changes affect balance point of meterbridge

Posted by Akanksha Dhawaliker 6 years, 1 month ago

CBSE > Class 12 > Physics

1 answers

Vaishnavi Kalvakuntla 6 years, 1 month ago

Change in resistance

0Thank You

ANSWER

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

Posted by Sweta Sinha 6 years, 1 month ago

CBSE > Class 12 > Physics

7 answers

Killer Xmarty 6 years, 1 month ago

Yssssss

0Thank You

Dhruv Rajput 6 years, 1 month ago

Yes bro only in yor syllabus?

0Thank You

Rituporna Gohain 6 years, 1 month ago

0Thank You

Ayan Ali 6 years, 1 month ago

1Thank You

Gaurav Rawat 6 years, 1 month ago

1Thank You

Muskaan Vig 6 years, 1 month ago

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

1Thank You

Shruti Jha 6 years, 1 month ago

Yes.

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ANSWER

Shruti pdha do?????

Posted by Rameez Khan 6 years, 1 month ago

CBSE > Class 12 > Physics

15 answers

Killer Xmarty 6 years, 1 month ago

Love

1Thank You

Shruti Jha 6 years, 1 month ago

Kyaaa hua?

0Thank You

Killer Xmarty 6 years, 1 month ago

0Thank You

Shruti Jha 6 years, 1 month ago

Rameez??

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Killer Xmarty 6 years, 1 month ago

Plz

0Thank You

Killer Xmarty 6 years, 1 month ago

Loove u

0Thank You

Shruti Jha 6 years, 1 month ago

Kya hmm? What happened to you ?

0Thank You

Killer Xmarty 6 years, 1 month ago

Hmm jaan

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Shruti Jha 6 years, 1 month ago

Kyaaa?

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Shruti Jha 6 years, 1 month ago

Main kese padha sakti hu???

0Thank You

Rameez Khan 6 years, 1 month ago

I love u

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Shruti Jha 6 years, 1 month ago

Main kese padha sakti hu?

0Thank You

Rameez Khan 6 years, 1 month ago

Ky kr ri ho

1Thank You

Rameez Khan 6 years, 1 month ago

Kuch bhi

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Shruti Jha 6 years, 1 month ago

Main kya padhau?

0Thank You

ANSWER

Is van de graff generator in syllabus

Posted by Pk Rabari 6 years, 1 month ago

CBSE > Class 12 > Physics

4 answers

Priya Aggarwal 6 years, 1 month ago

1Thank You

Rameez Khan 6 years, 1 month ago

Nooo

1Thank You

Shruti Jha 6 years, 1 month ago

Noo

1Thank You

Tamanna Sharma 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

34 answers

Killer Xmarty 6 years, 1 month ago

Tmse jn

0Thank You

Shruti Jha 6 years, 1 month ago

???

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Shruti Jha 6 years, 1 month ago

Hahah sahi hain pragati!

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Killer Xmarty 6 years, 1 month ago

Tmse

0Thank You

Navneet . 6 years, 1 month ago

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

1Thank You

Shruti Jha 6 years, 1 month ago

Kis se hua hain rameez?

0Thank You

Shruti Jha 6 years, 1 month ago

Means Pragati is only Avneet?

1Thank You

Killer Xmarty 6 years, 1 month ago

Pyaar

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Shruti Jha 6 years, 1 month ago

Rameez kya hua hain tumko?

0Thank You

Shruti Jha 6 years, 1 month ago

Okay okay! I remember now. ??

0Thank You

Navneet . 6 years, 1 month ago

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

1Thank You

Killer Xmarty 6 years, 1 month ago

Wht

0Thank You

Navneet . 6 years, 1 month ago

U remember me or not??

1Thank You

Shruti Jha 6 years, 1 month ago

Karti thi

0Thank You

Navneet . 6 years, 1 month ago

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

0Thank You

Shruti Jha 6 years, 1 month ago

Pragati whom you remember ? Me?

0Thank You

Navneet . 6 years, 1 month ago

Yeah I remember u from 10th grade ?

0Thank You

Shruti Jha 6 years, 1 month ago

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

0Thank You

Shruti Jha 6 years, 1 month ago

Yes Avneet!

0Thank You

Rameez Khan 6 years, 1 month ago

Shruti yrr jn

0Thank You

Rameez Khan 6 years, 1 month ago

Yrr but why they r rplying...

0Thank You

Shruti Jha 6 years, 1 month ago

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

0Thank You

Navneet . 6 years, 1 month ago

Shruti u r old user n

1Thank You

Shruti Jha 6 years, 1 month ago

We are also same, Avneet!?

1Thank You

Navneet . 6 years, 1 month ago

Ooo hello abuse kise kr rha

0Thank You

Rameez Khan 6 years, 1 month ago

Bhk saale

0Thank You

Navneet . 6 years, 1 month ago

Yess ??

1Thank You

Rameez Khan 6 years, 1 month ago

Babes

1Thank You

Rameez Khan 6 years, 1 month ago

U also

1Thank You

Rameez Khan 6 years, 1 month ago

Yup

1Thank You

Shruti Jha 6 years, 1 month ago

Ahaa! ?

0Thank You

Shruti Jha 6 years, 1 month ago

Ahaa! We are same.

0Thank You

Rameez Khan 6 years, 1 month ago

????

2Thank You

Rameez Khan 6 years, 1 month ago

Yesss

1Thank You

ANSWER

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

Posted by Meghna Sharma 6 years, 1 month ago

CBSE > Class 12 > Physics

1 answers

Rameez Khan 6 years, 1 month ago

Meeeeee

0Thank You

ANSWER

??????

Posted by Shruti Jha 6 years, 1 month ago

CBSE > Class 12 > Physics

29 answers

Killer Xmarty 6 years, 1 month ago

0Thank You

Shruti Jha 6 years, 1 month ago

Okay!

0Thank You

Killer Xmarty 6 years, 1 month ago

Yes

0Thank You

Shruti Jha 6 years, 1 month ago

Areeh are you ok?

0Thank You

Killer Xmarty 6 years, 1 month ago

Plz

0Thank You

Shruti Jha 6 years, 1 month ago

Main kya padhau?

0Thank You

Shruti Jha 6 years, 1 month ago

Padh rahi hu filhal!

0Thank You

Rameez Khan 6 years, 1 month ago

Acha hme pdha dijiye jaan

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Shruti Jha 6 years, 1 month ago

Padh rahi hu filhal

0Thank You

Rameez Khan 6 years, 1 month ago

Kya kr ri ho babes

0Thank You

Shruti Jha 6 years, 1 month ago

Kya batau?

0Thank You

Rameez Khan 6 years, 1 month ago

Okk...aur btaye

0Thank You

Shruti Jha 6 years, 1 month ago

I am also good!

0Thank You

Rameez Khan 6 years, 1 month ago

Fine...aap btai

0Thank You

Shruti Jha 6 years, 1 month ago

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

0Thank You

Rameez Khan 6 years, 1 month ago

Kya hua

0Thank You

Shruti Jha 6 years, 1 month ago

Haha Cool than!

1Thank You

Shruti Jha 6 years, 1 month ago

I am too formal with everyone!

0Thank You

Shruti Jha 6 years, 1 month ago

It's not about Sorry, Meghna! Chillax.

0Thank You

Shruti Jha 6 years, 1 month 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, 1 month ago

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

0Thank You

Meghna Sharma 6 years, 1 month ago

Are shruti meine aapko nhi bola

0Thank You

Shruti Jha 6 years, 1 month ago

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

0Thank You

Meghna Sharma 6 years, 1 month ago

Abhi board ke exams bhi dene kaise handle kroge ayaan

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Meghna Sharma 6 years, 1 month ago

Aunty ji itni tension mat lo

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Shruti Jha 6 years, 1 month ago

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

0Thank You

Meghna Sharma 6 years, 1 month ago

Kachu bat na h

0Thank You

Meghna Sharma 6 years, 1 month ago

Shruti

0Thank You

Meghna Sharma 6 years, 1 month ago

Sab saras che

0Thank You

ANSWER

Define eddy current and give 2 of its application

Posted by Swagata Paul 6 years, 1 month ago

CBSE > Class 12 > Physics

1 answers

Muskaan Vig 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics

1 answers

Muskaan Vig 6 years, 1 month 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, 1 month ago

CBSE > Class 12 > Physics