Question

A horizontal power line carries a current of 5960 A from south to north. Earth's magnetic field (77.6 µT) is directed toward the north and is inclined downward at 70.0° to the horizontal. Find the (a) magnitude and (b) direction of the magnetic force on 91.0 m of the line due to Earth's field.

Answer 1

Explanation:

It is given that,

Current flowing, I = 5960 A

Magnetic field, $B=77.6\ \mu T=77.6\times 10^{-6}\ T$

1. Angle between Magnetic field and horizontal is 70°. We need to find the magnetic force on 91.0 m of the line due to Earth's field. Magnetic force is given by :

$F=ILB\ sin\theta$

$F=5960\times 91\times 77.6\times 10^{-6}\times sin(70)$

F = 39.54 N

2. The direction of magnetic force can be calculated using Fleming's left hand rule, the direction of magnetic force is in west direction.