The magnetic force per unit length on a wire carrying a current of 10 A and making an angle of `45^@` with the direction of a uniform magnetic field of 0.20 T is

Options

A. `2 sqrt(2) Nm^(-1)`
B. `(2)/(sqrt(2)) Nm^(-1)`
C. `(sqrt(2))/(2) Nm^(-1)`
D. `4 sqrt(2) Nm^(-1)`

Answer

B

Explanation

I = 10 A, `theta = 45^(@)`, B = 0.2 T
`therefore vec(F) = 1 vec(l) xx vec(B) rArr F = I//B sin theta`
`therefore" "(F)/(l) = IB sin 45^(@) = 10 xx 0.2 xx (1)/(sqrt(2)) = (2)/(sqrt(2)) Nm^(-1)`