Question

Charges are placed on the vertices of a square as shown. Let $\overrightarrow{E}$ be the electric field and V the potential at the centre. If the charges on A and B are interchanged with those on D and C respectively, then

• A. $\overrightarrow{E}$changes, V remains unchanged
• B. $\overrightarrow{E}$remains unchanged, V changes
• C. Both$\overrightarrow{E}$ and V change
• D. $\overrightarrow{E}$ and V remain unchanged

Answer 1

Answer: (B)

$\overrightarrow{E}$remains unchanged, V changes

Answer 2

Due q₁, electric feed at P(E₁) = $\frac { 1 } { 4 \pi \in _ { 0 } }$ $( \hat { \mathrm { i } } )$

q₂ electric fed at P(E₂) = $\frac { q _ { 2 } } { b ^ { 2 } }$

At P

\ tanq = = = × = 2