# Homework Help: Help me how to solve this problem ?(e.m.f)

1. Aug 6, 2008

### girl21girl

help me how to solve this problem ??(e.m.f)

A rectangular loop with sides of length a= 1.80 cm and b= 2.10 cm is placed near a wire that carries a current that varies as a function of time: it=2.92 + 1.19t2 where the current is in Amperes and the time is in seconds. The distance from the straight wire to the closest side of the loop is d= 0.290 cm.

the figure is here : http://img171.imageshack.us/img171/5849/prob09awloop2aa6.gif [Broken]

1) What is the magnetic flux through the loop at time t= 2.50 seconds? (Define positive flux into the page.)

(mu0*I/2*pi)*b*ln[(d+a)/d]
=8.59×10-8 T*m^2

2) What is the induced e.m.f. in the loop at time t= 2.50 seconds?
(Note that positive emf is clockwise. Compute the rate of change of magnetic flux through the loop to get the e.m.f.. )

help me how to solve this problem ??

Last edited by a moderator: May 3, 2017
2. Aug 6, 2008

### Redbelly98

Staff Emeritus
Re: help me how to solve this problem ??(e.m.f)

What's the rate of change of magnetic flux through the loop? You can use your expression from part 1.

3. Aug 6, 2008

### Domnu

Re: help me how to solve this problem ??(e.m.f)

HINT: Maxwell's Equations... which equation has something regarding the change in magnetic flux?