The second one, air is a poor conductor. If it weren't it wouldn't be used as such in construction. It's not the best insulator, but is quite efficient, and much cheaper to include a layer of air inside a wall than to add additional layers of asbestos :)
Answer:
Explanation:
The emf induced in a straight conductor of length l moving with velocity v perpendicular to a magnetic field B is
E = Blv
where B, l and v are perpendicular. The emf, E is in volts
Magnetic field, B is in webers/m2
= 1.2 T
length is in meters
= 0.15 m
velocity, v is in m/sec
= 8 m/s
E = 1.2 × 0.15 × 8
= 1.44 V
B.
Using ohm's law,
V = I × R
I = 1.44/200
= 0.0072 A
C.
F = B × I × L
= 1.2 × 0.0072 × 0.15
= 0.001296 N
The power added by all 75 of them is (539 - 322) = 217 MW .
The AVERAGE power of each improved turbine is
( 217 / 75 ) = 2.8933 MW = 2,893.3 KW/unit .