Question

a sphere of radius R is having charge Q uniformly distributed over it the energy density of electric field in the air at distance r (greater thanR)is given by

Answer 1

The magnitude of electric field at a distance r, which is greater than the radius R, of a solid sphere having charge Q is given by the formula:

 

E = (k x Q )/ (r^2)

 

The volume enclosed by a sphere of radius r is given by the formula:

 

V = (4 x pi x r^3) / 3

 

Energy density is defined as the ratio of electric field intensity at a distance r and the volume occupied the sphere of radius r. It is given by the formula:

 

ED = E / V

ED = (3 x k x Q) / (16 x pi^2 x epsilon x r^5)

Answer 2

A sphere of radius R is having charge Q uniformly distributed over it the energy density of electric field in the air at distance r (greater than R) is given by:

E = σ2∈0E = σ2∈0

F = Edr = σ2∈0F = Edr = σ2∈0 (σdA) (σdA)

= FdA = σ2∈0FdA = σ2∈0 = P = P

Force = P × πR2 = P × πR2

= σ22∈0πR2 = σ22∈0πR2

= Q216π2R2πR22∈0 = Q216π2R2πR22∈0

= Q232π∈0R2Q232π∈0R2