# Homework Help: Increasing EMF in a coil

1. Oct 3, 2009

### bettysuarez

1. The problem statement, all variables and given/known data

This is the solution to one of the problems I came across:
In an AC generator, a coil spins in a magnetic field. Of the following choices, circle the
one that will not cause an increase in the EMF generated in the coil?
a. replacing the coil wire with one of lower resistance.
b. spinning the coil faster.
c. increasing the magnetic field.
d. increasing the number of turns of wire on the coil.
e. all of the above actions will increase the EMF.

• Lower resistance wire will not affect the EMF, which is
proportional to the rate of change of flux.
• It would however, increase the current possible.

I would like to know if EMF is the same as V = IR (Ohm's law)? Hence if resistance decreases, then EMF would decreased since V is proportional to R. Why then do the answers to this question say that resistance will not affect the induced EMF?

2. Relevant equations
EMF = (change of flux)/ time
V = IR

3. The attempt at a solution