Three charges `2q,-q,-q` are located at the vertices of an equilateral triangle. At the circumcentre of the triangle

Options

A. a)the field is zero but potential is non zero
B. b)potential is zero and the field is infinity
C. c)both the field and potential are non zero
D. d)the field is non zero but potential is zero

Answer

D

Explanation

Potential due to charge -q at A
`V_A=1/(4 pi epsi_0K) (-q)/(r^2)^(1//2)`
Potential due to charge -q at B
`V_B=1/(4 pi epsi_0K) (-q)/(r^2)^(1//2)`
Potential due to charge +2q at C
`V_C=1/(4 pi epsi_0K). (2q)/(r^2)^(1//2)`
Total potential at centre
`V=V_A+V_B+V_C`
V=0
From charge configuration at the centre electric field is non zero.