




Step 1: Analyze the electric field inside and outside the sphere.
- Inside the sphere \((r < R)\): Electric field increases linearly with r due to the uniformly distributed charge.
- Outside the sphere \((r ≥ R)\): Electric field decreases as \(\frac{1}{ r^2}\) , behaving like a point charge at the center.
Step 2: Draw the graph.
- Combine the two observations to get the correct graph for the electric field variation.
Final Answer: The correct graph is represented by option (4).
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Net dipole moment of a polar linear isotropic dielectric substance is not zero even in the absence of an external electric field. Reason
(R): In absence of an external electric field, the different permanent dipoles of a polar dielectric substance are oriented in random directions.
In the light of the above statements, choose the most appropriate answer from the options given below:
Two large plane parallel conducting plates are kept 10 cm apart as shown in figure. The potential difference between them is $ V $. The potential difference between the points A and B (shown in the figure) is: 

In the first configuration (1) as shown in the figure, four identical charges \( q_0 \) are kept at the corners A, B, C and D of square of side length \( a \). In the second configuration (2), the same charges are shifted to mid points C, E, H, and F of the square. If \( K = \frac{1}{4\pi \epsilon_0} \), the difference between the potential energies of configuration (2) and (1) is given by: