Electric Charges and Fields - Result Question 11

11. Point charges $+4 q,-q$ and $+4 q$ are kept on the $X$-axis at points $x=0, x=a$ and $x=2 a$ respectively. Then

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(a) only $-q$ is in stable equilibrium

(b) none of the charges is in equilibrium

(c) all the charges are in unstable equilibrium

(d) all the charges are in stable equilibrium.

Topic 2: Electric Field, Electric Field

Lines & Dipole

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Answer:

Correct Answer: 11. (c)

Solution:

  1. (c) Net force on each of the charge due to the other charges is zero. However, disturbance in any direction other than along the line on which the charges lie, will not make the charges return.