Question

An electric charge 10^–3mC is placed at the origin (0, 0) of X-Y co-ordinate system. Two points A and B are situated at ($\sqrt{2}$,$\sqrt{2}$) and (2, 0) respectively. The potential difference between the points A and B will be-

• A. 4.5 volt
• B. 9 volt
• C. Zero
• D. 2 volt

Answer 1

Answer: (C)

Zero

Answer 2

V_A =$\frac { \mathrm { kQ } } { \mathrm { r } _ { \mathrm { A } } }$, V_B = $\frac { \mathrm { kQ } } { \mathrm { r } _ { \mathrm { B } } }$

r_A = $\sqrt { ( \sqrt { 2 } - 0 ) ^ { 2 } + ( \sqrt { 2 } - 0 ) ^ { 2 } }$ = 2

r_B = $\sqrt { ( 2 - 0 ) ^ { 2 } + ( 0 - 0 ) ^ { 2 } }$ = 2

\ $\mathrm { V } _ { \mathrm { A } } - \mathrm { V } _ { \mathrm { B } } = 0$