Question

There is a long straight wire carrying current I = 497 amperes. At a distance of 0.6 meter away, a small piece of wire (length 1 cm) carries a current of 12 amperes in a direction parallel to the long wire. (a) Calculate the value of the B field generated by the long wire at the position of the small wire. B = T (b) Using your result for B just found, calculate the force on the small wire. F = N

Answer 1

Given

Current in the long wire I = 497 A

r = 1.3 m

Length of the small wire , L = 0.01 m

Current in the small wire , i = 12 A

a) Magnetic field given as

`B = (\mu_oI)/(2\pi r)`

`B=(4\pi * 10^(-7)* 497)/(2 * \pi * 1.3)`

B=0.000076 T

B=7.6 x 10⁻⁵ T

b)

We know that force F given as

F= I B L

The force on the small wire is

F= i . B L

F= 12 x 0.000076 x 0.01

F=912 x 10⁻⁸ N