Question

3. (a) What is the potential difference V_A ? V_B between two points A and B situated at 26.0 cm and 52.0 cm respectively from a 3.10 µC point charge?

(b) Where should the point B be moved to in order to increase this potential difference by a factor of two?

Answer 1

a) charge , q = 3.1 uC

Now ,for the potential difference

potential difference = k* q(1/r1 - 1/r2)

potential difference = 9 *10^9 * 3.1 *10^-6 * (1/.26 - 1/.52)

potential difference = 5.63 *10^4 V

b) for the difference to be two times of this factor

2 * 5.63 *10^4 = 9 *10^9 * 3.1 *10^-6 * (1/.26 - 1/r)

solving for r

r = -5.27 m

as r of negative is not possible ,

the correct answer is option 5