HCV EMI

Doubt is that must E always be greater than vBl

Although it has mentioned v is small, but B and l may be large enuf to be greater than E,

So the answers will differ.

IS my logic correct?

7 Answers

24
eureka123 ·

small velocity just means that initialy Emfinduced or u call motional emf will be low...so motion will be accelrated...due to which velocity will become larger..after that termainal velocity attained...and aftre that decelration when motiional emf >E

106
Asish Mahapatra ·

vel may be small but motional emf may exceed E cant it becasue motional; emf = vBL so even if v is small B and L may be large enuff.

In that case the directions will reverse in the questions act.

24
eureka123 ·

I never interpretted this ques that way..so cant help[2]

11
Devil ·

H'mmm, well interestingly, in that case for some velocity, the net emf in the circuit will turn out to be 0!

106
Asish Mahapatra ·

yeah !!

39
Pritish Chakraborty ·

I've done this before...but its not striking me as cleanly. Lets see..
The wire moving with a velocity v to the right in magnetic field B will have some emf of its own...if we could interpret the wire ab as having a potential drop, we could have a two battery circuit with emfs E and Bvl. Net emf becomes E - Bvl....resistance given is r.
I = (E - Bvl)/r , in the direction b to a.
The force would obviously be F = I l B sintheta, where sintheta = 1.
So F = I l B = (E - Bvl) l B/r
After some time t, E will equal Bvl as a maximum, and thus v = E/B l.
So indeed when the wire moves with constant velocity v = E/B l then the net emf becomes zero.
Make some sense?

106
Asish Mahapatra ·

im asking the doubt i know what HCV wants

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