a circular coil of radius 0.11m contains a single turn and is located in a constant magnetic field of magnitude 0.27T. the magnetic field has the same direction as the normal to the plane of the coil. the radius increase to 0.3m in a time of 0.08s.
a) Determine the magnitude of the emf induced in the coil
b) The coil has resistance of 0.7ohm. Find the magnitude of induced current.

Question

a circular coil of radius 0.11m contains a single turn and is located in a constant magnetic field of magnitude 0.27T. the magnetic field has the same direction as the normal to the plane of the coil. the radius increase to 0.3m in a time of 0.08s. 
a) Determine the magnitude of the emf induced in the coil 
b) The coil has resistance of 0.7ohm. Find the magnitude of induced current.

ujjwal · Answer

$$E=d \phi/dt$$$$\phi=BA Cos \theta$$ here theta=0
So, $$\phi=BA$$ Now give it a try.. Find change in area and respective change in flux.. divide it by time. you will get the Emf.. 
Once you have calculated the emf, use the formula I=V/R to find current..

kainui · Answer

I find that drawing a picture helps in nearly every physics problem I come across along with listing every variable I have.

r=.11m
B=.27T
etc...
|dw:1335504139971:dw|

This isn't a complete diagram, just something to give you a general idea of how I approach problems.