A long wire carries a current of 5A. An electron at a distance of 50 cm from this wire is moving with a speed of `10^(7)` m/s What is the force acting on the electron, when it moves directly towards the wire ?

Options

A. `3.2xx10^(-18)N`
B. `5xx10^(-17)N`
C. `6.4xx10^(-18)N`
D. `1.6xx10^(-18)N`

Answer

A

Explanation

The magnetic induction B near a straight conductor is given by
`B =(mu_(0))/(4pi)((2I)/(r))=(10^(-7)xx2xx5)/(5xx10^(-1))=2xx 10^(-6) Wb//m^(2)`
and the force,
`F=qvB sin theta =1.6 xx10^(-19)xx10^(7) xx2xx10^(-6)xxsin 90^(@)=3.2xx10^(-18) `newton