Question

Charge $Q$ is given to a spherical conductor of radius $R$. It is surrounded by a concentric conducting shell of inner radius $a$ and outer radius $b$. Corresponding electric field diagram will be:

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Given Data,

Charge $Q$ is given to a spherical conductor of radius $R$.

It is surrounded by a concentric conducting shell of inner radius $a$ and outer radius $b$.

We have to choose the corresponding electric field diagram.

Explanation of correct option,

Option $\left(A\right)$

1. The electric field line moves outwards from the positive charge and towards in negative charge.
2. The charge $Q$ given to the spherical conductor in the centre of radius $R$ is the positive charge. It generates a positive charge on the surface of radius $a$ and hence, the electric field line moves outwards from the sphere of radius $a$.
3. As the positive charge on the surface of radius $a$ the inner surface of the outer radius $b$ is negative this will generate the positive charge on the outer surface of radius $b$and hence, again the electric field line moves outwards from the sphere.

Hence, Diagram $\text{'}A\text{'}$ is the correct option.

Explanation of incorrect options,

Option $\left(B\right)$

1. In diagram $\left(B\right)$ we can see that Electric Field moves from the inner radius $a$ but there is no electric field lines in the outer radius $b$.

Option $\left(C\right)$

1. Electric Field can not reach directly to the outer radius $b$. It should have the first moved from the inner radius $a$.

Option $\left(D\right)$

1. The direction of the Electric Field is wrong in diagram $D$ since the Electric field line moves outwards from the positive charge but in the diagram $D$ the Electric Field line comes towards the positive charge.

Hence, the correct option is $\text{'}A\text{'}$.