PDA

View Full Version : Magnetic Field and induced current


bchl85
Dec22-04, 05:56 AM
Can anyone help me to do this problem. Thanks in advance.

A closed wire loop in the form of a square of side 4.0cm is mounted with its plane horizontal. The loop has a resistance of 2.0*10^(-3) ohm. The loop is situated in the magnetic field of strength 0.7 T directed vertically downwards.
When the field is switched off, it decreases to 0 at a uniform rate in 0.8s
What is:
a) The current induced in the loop.?
b) The energy dissipated in the loop during the change in the magnetic field?

Nylex
Dec22-04, 06:48 AM
What have you done so far? You have enough information to work out the EMF induced in the loop, so you can work out the current.

dextercioby
Dec22-04, 07:10 AM
Can anyone help me to do this problem. Thanks in advance.

A closed wire loop in the form of a square of side 4.0cm is mounted with its plane horizontal. The loop has a resistance of 2.0*10^(-3) ohm. The loop is situated in the magnetic field of strength 0.7 T directed vertically downwards.
When the field is switched off, it decreases to 0 at a uniform rate in 0.8s
What is:
a) The current induced in the loop.?
b) The energy dissipated in the loop during the change in the magnetic field?

Here are some formulas that might help:
U_{induced}=-\frac{\Delta \Phi_{mag}}{\Delta t}
\Phi_{mag}=:\vec{B}\cdot \vec{S}
I_{induced}=\frac{U_{induced}}{R}
W=U_{induced}I_{induced}t

Daniel.

PS.The problem is very easy.Hopefully u'll solve it by yourself...