Question 772: Electrostatics & Capacitance

Question

As per the diagram a point charge +q is placed  at the origin O. Work done in taking another point charge $$-$$Q from the point A [coordinates (0, $$a$$)] to another point B

Accepted Answer

Work done is equal to zero because the
potential of A and B are the same = $${1 \over {4\pi {\varepsilon _0}}}{q \over a}$$
No work is done if a particle does not change its potential energy.
i.e. initial potential energy = final potential energy.

Answer

zero

Answer

$$\left( {{{qQ} \over {4\pi {\varepsilon _0}}}{1 \over {{a^2}}}} \right).\sqrt 2 a$$

Answer

$$\left( {{{ - qQ} \over {4\pi {\varepsilon _0}}}{1 \over {{a^2}}}} \right).\sqrt 2 a$$

Answer

$$\left( {{{qQ} \over {4\pi {\varepsilon _0}}}{1 \over {{a^2}}}} \right).{a \over {\sqrt 2 }}$$

Electrostatics & Capacitance

As per the diagram a point charge +q is placed at the origin O. Work done in taking another point charge $-Q from the point A [coordinates (0, a$)] to another point B

Choose the correct answer: