1.

Loop `A` of radius `rgtgtR` moves toward loop `B` with a constant velocity `V` such a way that their planes are always parallel. What is the distance between the two loops `(x)` when the induced emf in loop `A` is maximum? A. `R`B. `R/sqrt2`C. `R/2`D. `R(1-1sqrt2)`

Answer» Correct Answer - C
`phi_(A)=(mu_(0)ipiR^(2))/(2pi(R^(2)+x^(2))^(3//2))pir^(2)`
`E_(A)=-(dphi)/(dt)=(mu_(0)ipi)/2R^(2)r^(2)(-3//2)(R^(2)+x^(2))^(5//2)2x(v)`
`E_(A)` is maximum when `(dE_(A))/(dx)=0`
`rArr d/(dx)x/(R^(2)+x^(2))^(5//2)=0`
or `(R^(2)+x^(2))^(-5//2)-(5x)/2(R^(2)+x^(2))^(3//2)` 2x=0 or `R^(2)+x^(2)-5 x^(2)=0`
or `x=R/2`


Discussion

No Comment Found

Related InterviewSolutions