A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.60 T in a time of 0.45 s. The wire has a resistance per unit length of 3.3 x 10-2 ohm/m. What is the average electrical energy dissipated in the resistance of the wire.(adsbygoogle = window.adsbygoogle || []).push({});

ok so this is what i have:

r= 13cm= .13m

change in t= .45s

B= .60T

restitance per unit length= 3.3 x 10^-2

N= 1

then i tried:

magnetic flux= BAcos= (.60T)(530.9m^2)= 318.6

emf= -N(change in magnetic flux/ change in time)= -1(318.6/.45s)= -708

here is where i get really confused:

R= restitance per unit length (L/A)

does this mean i should do:

R= 3.3 x 10-2 ohm/m (2 pi .13)/(.13^2 pi)???

or is it just R= 3.3 x 10-2 ohm/m (.13m)??? because the units work out this way...

once i figure that out i would do:

I=emf/R ---->

P=I(emf) ------->

E=Pt and that would give me energy

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# Faraday's law of electomagnetic induction

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