What is the electric potential at a distance of 9 cm from 3 nC ?

Options

A. 300 V
B. 270 V
C. 30 V
D. 3 V

Answer

A

Explanation

Electric potential due to a point charge Q at a distance r from it, is
`V=(1)/(4 pi epsilon_(0)) Q/r`
Here, `Q=3 nC = 3 xx 10^(-9)C`
`r=9cm = 9xx10^(-2)m`
`:.V=(9xx10^(9)xx3xx10^(-9))/(9xx10^(-2))=300V`