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PMMC Instrument Part 1 (in Hindi)
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In this lesson I've discussed basic introduction about PMMC instrument.

Pawan Chandani is teaching live on Unacademy Plus

Pawan Chandani
Faculty of GATE/ESE (Electrical Engineering) , Also a YouTuber and teaches Electrical Eng. subjects on YouTube | Jony Ive Award Winner

U
Unacademy user
fantastic explanation mam
sir I just want to ask sir for university exam should I follow this whole course sir for IN branch.
Pawan Chandani
8 months ago
Absolutely...
RA
Eddy current produce due to time varying flux i.e AC in nature.If it is connected accross DC voltage , it will behave as a magnet and flux remains constant due to DC supply.How EDDY current will produce and oppose this motion.Sir correct me if I am wwrong.
Pawan Chandani
a year ago
Here eddy current induced due to motion of the coil not due to time varying flux because According to Faraday's law there should be relative motion between conductor or flux...either flux will be time varying or conductor will move...ok...so here flux is constant because we have used permanent magnet...ok and according to Lenz law resultant always opposes it's cause...so here cause of induction is Motion of the coil or former.....so induced eddy current opposes the motion of the former so that we get damping torque...thats simple.
RA
Rezwan Ahemmed
a year ago
Thank you so much.
Pawan Chandani
a year ago
welcome...then plz do rate and review this course
RA
Rezwan Ahemmed
a year ago
Sir,please complete this EEM course according to GATE and ESE syllabus.Your explanation was very good.After completing this EEM course ,post more question related to EEM.
Pawan Chandani
a year ago
sure :)
sir please confirm me whether it is Eddy current damping or electromagnetic damping in pmmc??
Pawan Chandani
a year ago
damping technique that we use in pmmc instrument is Eddy current damping. but mechanism of both the damping that is Eddy current and electromagnetic damping are same in one damping torque is proportional to current and in another damping torque is proportional to voltage. sometimes in options when Eddy current damping is not present then we should mark electromagnetic damping. but most correct answer is Eddy current damping.
Akarsh Kumar
a year ago
thank you
Communication system me hum rectifier instrument ka use hi Q krte h ..analog ka use Q nhi krte ..yadi analog instruments ka use kre to kya disadvantage hoga
Pawan Chandani
a year ago
because electrostatic voltmeter and MI instrument cannot measure high frequency or audio signals... only pmmc instrument can measure high frequency signals but pmmc instrument can measure only DC value or average value but our high frequency signals or audio signals are AC signals... so that first we rectify AC signals and convert them into DC then measure it from pmmc instrument and after that we calibrate scale according to appropriate form factor.
Ravikumar Kumar
a year ago
sir,what is the reason we can't measure high frequency or audio signal by using electrostatic or mi instruments
Pawan Chandani
a year ago
their construction doesn't allow to measure high frequency signals they can work only for power frequency that means 50 Hertz
Ravikumar Kumar
a year ago
OK sir thank you ..
DS
HELLO SIR , HERE U TOLD THAT FORMAR CUT THE FLUX , MEANS ? and sir here magnetic flux is change with time so that emf is induced E=-(dphi/dt)and i=(E/r) i.e. eddy current? sir give me comment if i am wrong.
Pawan Chandani
a year ago
I am not understanding what you want to ask me.... please clearly mention which point you are not getting.... you can ask your query in Hindi also.
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  2. Hello! - Pawan Chandani Done B. Tech from RTU University from EE department "Two times GATE and SSC JE qualified. Providing Coaching for GATE and ESE aspirant in EE stream. .Provide Content of Electrical on YOUTUBE. -You can follow me at: https://unacademy.com/user/pawanchandani1990


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