(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A generator uses a coil that has 100 turns and a 0.50-T magnetic field. The frequency of this generator is 60.0 Hz, and its emf has an rms value of 120 V. Assuming that each turn of the coil is a square (an approximation), determine the length of the wire from which the coil is made.

2. Relevant equations

Emf = NABwsin(wt) -- not sure if i should utilize sin(wt)?

and w = 2(pi)f

3. The attempt at a solution

I notice that the problem includes emf as an rms value. I figure that it is sq(2). Then, I figure out the w - the value is 377.

The problem setup so far is...

sq(2)*120V = (100 turns)(A)(0.50-T)(377) sin (377*.02) ---- i figured time, t by using the frequency T = 1/f equation.

Solving for A, I get A = .069 m^2. I then solve for the radius using A = (pi)r^2 and get r = .148 m. Then, I plug the r into L = 2(pi)r to get length. My answer isL = .931 m (final answer).

Book Answer: 38 m

Now the answer I was given doesn't match with what i was given. I am guessing whether I should multiply by 100 since there are that many turns in the coil? Or just ignore the sin(wt) part? I just don't know how to fix this problem. My book does a horrible job explaining how to approach generator problems.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Electric Generator Problem

**Physics Forums | Science Articles, Homework Help, Discussion**