Charge of uniform density 50 nC/m3 is distributed throughout the inside of a long nonconducting cylindrical rod (radius = 5.0 cm). Determine the magnitude of the potential difference of point A (2.0 cm from the axis of the rod) and point B (4.0 cm from the axis).

magnitude of the potential difference is  -1.7 V

Explanation:

given data

Charge of uniform density σ = 50 nC/m³ = 50 × C/m³

radius = 5.0 cm = 0.05 m

point A = 2 cm = 0.02 m

point B = 4 cm = 0.04 m

solution

as we know inside rod, we construct a cylindrical Gaussian surface of length L and radius r  around the axis.

so  electricfield is always perpendicular to the lateral surface area -2πrL

so that

E =   ..........1

E =    

E =  

Δv = - ∫ E.dr

Δv =          

put here value

Δv =        

Δv =  

Δv =  

Δv  = -1.7 V

answer; /// i believe that the correct answer is (c)

the average speed is 24.57 km/hr