Question

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

• A. 9 volts
• B. zero
• C. 2 volts
• D. 4.5 volts

Answer 1

Answer: (B)

zero

Answer 2

V_A = $\frac { \mathrm { kq } } { \mathrm { r } }$ = $\frac { \mathrm { kq } } { \sqrt { ( \sqrt { 2 } ) ^ { 2 } + ( \sqrt { 2 } ) ^ { 2 } } }$ = $\frac { \mathrm { kq } } { 2 }$

V_B = $\frac { \mathrm { kq } } { \mathrm { r } ^ { \prime } }$ = $\frac { \mathrm { kq } } { \sqrt { ( 2 ) ^ { 2 } + ( 0 ) ^ { 2 } } }$ = $\frac { \mathrm { kq } } { 2 }$

\ V_A – V_B = 0