A helicopter hovers above the north magnetic field pole in a magnetic filed of magnitude 0.5G perpendicular to the ground. The helicopter rotors are 10m long, are made of aluminum, and rotate about the hub with a rotational speed of 10 000 rpm. What is the potential difference form the hub of the to to the end?

I don't know what to do for this problem , what I first did was to transform rpm to m/s

2*pi*10m*10 000 rpm*(1min/60s)

and got 10742 m/s

I don't know where to go from there.

1 answer

Eeach rotor=-d PHI/dt=-B*dA/dt
= 1E-4 tesla*PI*10^2/timeper revolution

what is the time per reveloution?

rpm to rps=10000/60

time= 1/rps=60/1E4

E=1E-4*PI*100*1E4/60=314/60 volt for each rotor, from center to end,so total EMF is twice that.