AIIMS2019PhysicsCurrent Electricity
The current density in a solid cylindrical wire of radius R , as a function of radial distance r is given by J(r)=J₀ (1- r R ) . The total current in the radial region r=0 to r= R 4 will be
Options
- A5 J₀ R^2 32
- B5 J₀ R^2 96
- C3 J₀ R^2 94
- DJ₀ R^2 128
Correct answer
B. 5 J₀ R^2 96
Step-by-step solution
aligned & : d i=J d A=J₀ (1- r R ) 2 r d r i & = _ r=0 ^ r= R 4 J₀ (1- r R ) 2 r d r & = J₀ 5 R^2 96 aligned