Question

When a slab of insulating material $4\text{ mm}$ thick is introduced between the plates of a parallel plate capacitor of separation $4\text{ mm}$, it is found that the distance between the plates has to be increased by $3.2\text{ mm}$ to restore the capacity to its original value. The dielectric constant of the material is __________. Fill in the blank with the correct answer from the options given below.

• A. 2
• B. 5
• C. 3
• D. 7

Hint:

Dielectric constants ($K$) are always greater than 1. If your calculation results in $K < 1$, check if you've swapped the shift ($\Delta d$) and the thickness ($t$) in the formula.

Answer 1

The Correct Option is B