Determine the potential at a point 0.50 m (i) from a`+20 muC` potential charge (ii) from a`-20 muC` point charge.

Explanation

The potential due to a point charge is given by `V= ( kQ)/(r )`
(a) At a distance of 0.50 m from a positive `20 mu C` charge, the potential is
`V = ( kQ)/( r ) = ( 9.0 xx 10^(9) N. m^(2) //C^(2)) (( 20 xx 10^(-6)C)/( 0.50 m)) = 3.6 xx 10^(5) V `
(b) For the negative charge.
`V = ( 9.0 xx 10^(9)N. m^(2) //C^(2)) ((-20 xx 10^(-6) C )/( 0.50 m)) = - 3.6 xx 10^(5) V`