Question

A spherical straight has a radius of 14.0 cm and a charge of 26.0 uC.Calculate the electric field and the electric potential at(a)r=10.0 cm (b)r=20.0 cm, and (c)r=14.0 cm from the centre.

Answer 1

a) Since the sphere is conducting, the electric field inside it $r=0.1\ m<R$ is zero

$$E=0\frac{N}{C}$$

$$V=8.99\cdot 10^9\frac{26\cdot 10^{-6}}{0.14}=1.67\cdot 10^{6}V$$

b)

$$E=8.99\cdot 10^9\frac{26\cdot 10^{-6}}{0.2^2}=5.84\cdot 10^{6}\frac{N}{C}$$

$$V=8.99\cdot 10^9\frac{26\cdot 10^{-6}}{0.2}=1.17\cdot 10^{7}V$$

c)

$$V=8.99\cdot 10^9\frac{26\cdot 10^{-6}}{0.14}=1.67\cdot 10^{6}V$$

$$E=8.99\cdot 10^9\frac{26\cdot 10^{-6}}{0.14^2}=1.19\cdot 10^{7}\frac{N}{C}$$