Plz solve 5th sum

equivalent current due to circular motion of α-particle :-   current = charge passing per unit time  = 2e/T...........(1)

 

where 2e is the charge of α-particle and T is time period of revolution , T = 2πr/v ...................(2)

 

where r is radius of circular orbit and v is speed of alpha particle

 

From eqn.(1) and eqn.(2), we get current i =  2e / (2πr/v)  = (  e v ) / (  π r ) ....................(3)

 

magnetic field B at centre of circular motion of α-particle is given by,   B = ( μ_o i ) / ( 2 r )  ......................(4)

 

using eqn.(3) and (4),  B  = ( μ_o e v ) / ( 2π r² )  = ( 2 ×10^-7 × 2 × 1.602 × 10^-19 × 2 × 10⁶ ) / ( 2 × 10^-20 ) = 6.4 T