Rectangular coil rotating in magnetic field

[ihateblackbox]

Homework Statement

A rectangular coil of 80 turns has an area of 0.01m^2. It rotates @ 3000rpm about one of its in plane axes, in a uniform magnetic field having B=1.5T. Calculate the rms voltage generated.

Homework Equations

1 Tesla= 1 Weber/m^2.
Change in flux of 1 Weber per second = 1 Volt induced.

The Attempt at a Solution

(80*0.01*3000*1.5)/60 = change in flux of 60 Wb/s. ==> 60V. 60/[2sqrt(2)]=15sqrt(2)Vrms.

This is not the right answer. The answer is 267Vrms.

 

[rock.freak667]

3000 rpm, you need to convert that to rad/s. You didn't multiply by π.

 

[ihateblackbox]

3000 rpm, you need to convert that to rad/s. You didn't multiply by π.

I get the right answer then, but don't understand why you would do that?

 

[rock.freak667]

In the formula E(max)=NBAw, B,A and w need to be in SI units (or at least derived SI units) for the units to produce the Volt on the left hand side.

So rpm would need to be converted to radians per second.

 

[ihateblackbox]

In the formula E(max)=NBAw, B,A and w need to be in SI units (or at least derived SI units) for the units to produce the Volt on the left hand side.

So rpm would need to be converted to radians per second.

OK. Many thanks.