g Consider a (12.5 A) cm long metal bar moving horizontally across a vertical magnetic field at a speed of (2.40 B) m/s. The magnetic field strength is 2.45 T. If the ends of the bar are connected to a (1.20 C) ohm resistor, find the power dissipated in the resistor while the bar is moving. Calculate the answer in watts (W) and rounded to three significant figures.

Explanation:

emf   due to movement of a rod of length L in a perpendicular to magnetic field B with velocity v is given as

emf = BLv

Putting in the given values ,

E = 2.45 x 12.5 x 10⁻² x 2.4

= .735 V

This emf produces current in resistance . Power consumed by resistance

V² / R where R is resistance , V is emf induced .

Power = .735² / 1.2

= .45 W .

total distance/total time

(85 + 82)/(5+3)

167/8

20 just over