Electrostatics Question 333
Question: Three charges $ 2q,-q,-q $ are located at the vertices of an equilateral triangle. At the centre of the triangle [MP PET 1985; J & K CET 2004]
Options:
A) The field is zero but potential is non-zero
B) The field is non-zero but potential is zero
C) Both field and potential are zero
D) Both field and potential are non-zero
Show Answer
Answer:
Correct Answer: B
Solution:
Obviously, from charge configuration, at the centre electric field is non-zero.
Potential at the centre due to 2q charge $ V _{2q}=\frac{2q}{r} $
and potential due to -q charge $ {V _{-q}}=-\frac{q}{r} $ (r = distance of centre point)
Total potential $ V=V _{2q}+{V _{-q}}+{V _{-q}}=0 $
