Question

A long electric cable is suspended above the earth and carries a current of 345 A parallel to the surface of the earth. The earth’s magnetic field has a value of 5.6 × 10−5 T and makes an angle of 88.2 ◦ with respect to the cable. What is the magnitude of the force f exerted on a cable of length 46.9 m due to the earth’s magnetic field? Answer in units of N

Answer 1

0.906 N

Step-by-step explanation:

Formula for magnetic force acting on current carrying cable:

`F = IBLsin(\theta)`

Where I = 345A is the current in the wire, B =
`5.6*10^(-5) T` is the magnetic magnitude generated by Earth. L = 46.9 m is the cable length.
`\theta = 88.2^o` is the angle between vector B and cable direction.

`F = 345*5.6*10^(-5)*46.9*sin(88.2^o)`

`F = 0.906 N`