Why Does Changing Magnetic Field Direction Affect Current in a Wire Loop?

[Destrio]

Homework Statement

A loop of wire of aream 0.32m^2 is palced in a 0.75 T magnetic field. The magnetic field is changed to 0.35 T in the opposite direction in 0.45 s . What is the magnitude of the current through the 15 ohm resistor.

Homework Equations

emf = -N (flux / time)

The Attempt at a Solution

emf = (-1) [(.35T)(.32m^2)-(.75T)(.32m^2)]/(.45s)
emf = .284 V
V = IR
I = .284 V / 15ohm
I = .019 A

.019 is the wrong answer in the multiple choice
the correct answer is supposed to be 0.052 A

Thanks

 

[OlderDan]

Homework Statement

A loop of wire of aream 0.32m^2 is palced in a 0.75 T magnetic field. The magnetic field is changed to 0.35 T in the opposite direction in 0.45 s . What is the magnitude of the current through the 15 ohm resistor.

Homework Equations

emf = -N (flux / time)

The Attempt at a Solution

emf = (-1) [(.35T)(.32m^2)-(.75T)(.32m^2)]/(.45s)
emf = .284 V
V = IR
I = .284 V / 15ohm
I = .019 A

.019 is the wrong answer in the multiple choice
the correct answer is supposed to be 0.052 A

Thanks

Looks like you have not computed the change in field correctly.