Assertion: Electric field intensity inside a solid non-conducting uniformly charged solid sphere increases linearly inside the sphere.
Reason: Electric field intensity outside the solid non-conducting uniformly charged solid sphere is same as the electric field generated by a point charge kept at the centre of sphere.

• If both assertion and reason are correct and reason is a correct explanation of the assertion.
• If both assertion and reason are correct but reason is not the correct explanation of assertion.
• If assertion is correct but reason is incorrect.
• If assertion is incorrect but reason is correct.

The assertion and reason provided relate to the behavior of electric fields in a uniformly charged solid sphere. Let's break down both statements.

Assertion Analysis

The assertion states that the electric field intensity inside a solid non-conducting uniformly charged sphere increases linearly. This is indeed correct. Within the sphere, the electric field intensity (E) at a distance (r) from the center is given by the formula:

• E = (1/4πε₀) * (Q * r) / R³, where Q is the total charge, R is the radius of the sphere, and ε₀ is the permittivity of free space.

This shows that E increases linearly with r, confirming the assertion.

Reason Evaluation

The reason states that the electric field outside the sphere is equivalent to that of a point charge located at the center. This is also correct, as the electric field outside a uniformly charged sphere behaves like that of a point charge at its center, following the formula:

• E = (1/4πε₀) * (Q / r²), where r is the distance from the center of the sphere.

Relationship Between Assertion and Reason

While both statements are correct, the reason does not explain why the electric field inside the sphere increases linearly. The linear increase is due to the distribution of charge within the sphere, not the behavior of the field outside it.

Final Conclusion

Thus, the correct evaluation is: both the assertion and reason are correct, but the reason does not provide the correct explanation for the assertion.