A long straight metal rod has a very long hole of radius a drilled parallel to rod as shown in the figure. If the rod carries a current `i`. Find the magnetic field `(a)` on the axis of the rod. `(b)` on the axis of the hole.

Answer

deviation `=pi-2 tan^(-).(mv_(0))/(qBR)`

Explanation

`qv_(0)B=(mv_(0)^(2))/(r),r=(mv_(0))/(qB)`
By `Delta ABO`
`tan alpha=(r)/(R)impliesalpha=tan^(-1).(r)/(R)=tan^(-1).(mv_(0))/(qBR)`
, deviation `=pi-2alpha=pi-2 tan^(-1).(mv_(0))/(qBR)`