Question

At a certain location in the Philippines, Earth's magnetic field of 39 μT is horizontal and directed due north. Suppose the net field is zero exactly 2.0 cm above a long straight, horizontal wire that carries a constant current. (a) What is the magnitude of the current?

Answer 1

the magnitude of current is 3.9 A

Step-by-step explanation:

given,

earth magnetic field = 39 μT

= 39 × 10⁻⁶ T

distance r = 2 cm

= 0.02 m

Using equation

`B = (\mu_0 i)/(2\pi r)`

`i = (2\pi r B)/(\mu_0)`

`i = (2\pi* 0.02* 39 * 10^(-6))/(\mu_0)`

`i = (2\pi* 0.02* 39 * 10^(-6))/(4\pi 10^(-7))`

= 3.9 A

hence, the magnitude of current is 3.9 A