From a homogeneous and isotropic dielectric material of dielectric constant ∈r, a small volume element is taken out creating a cavity. The field can be kept homogeneous if Di. (i.e., electric flux density inside the cavity) and D0 (i.e., electric flux density outside the cavity) are such that

• D0 = Di
• either (a) or (b)

Correct Answer:

Explanation:

Since the field is homogeneous .