Which of following statement (s) is/are correct? (A) If electric field due to a point charge varies

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2. Electric Potential and Capacitance

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Which of the following statement$(s)$ is/are correct?

$(A)$ If the electric field due to a point charge varies as $r^{-25}$ instead of $r^{-2}$, then the Gauss law will still be valid.

$(B)$ The Gauss law can be used to calculate the field distribution around an electric dipole.

$(C)$ If the electric field between two point charges is zero somewhere, then the sign of the two charges is the same.

$(D)$ The work done by the external force in moving a unit positive charge from point $A$ at potential $V_A$ to point $B$ at potential $V_B$ is $\left(V_B-V_A\right)$.

A

$(B,D)$

B

$(C,D)$

C

$(A,D)$

D

$(B,D)$

(IIT-2011)

Solution

Correct Answer – $C::D$

$(a)$ is not correct because it is valid only when $E \propto r^{-2}$

$(b)$ is not correct

$(c)$ is correct as between two point charges we will get a point where the electric field due to the two point charges cancel out each other.

$(d)$ is correct when the work done is without accelerating the charge.

Standard 12

Physics

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