Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Electrostatic Potential and Capacitance

Question:

A parallel plate capacitor with plate area A and separation d has charge Q. A slab of dielectric constant k is inserted in space between the plates almost completely fills the space. If E0 and C0 be the electric field and capacitance before inserting the slab, then

Options:

the electric field after inserting the slab is $\frac{E_0}{k}$

the capacitance after inserting the slab is $k C_0$

the induced charge on the slab is $\mathrm{Q}\left(1-\frac{1}{k}\right)$

All of the above

Correct Answer:

All of the above

Explanation:

Due to induced charges on dielectric electric field reduces to $\frac{E_0}{K}$ and hence potential difference decreases in same proportion. This results in increase in capacitances by K times.

$q'=q\left(1-\frac{1}{K}\right)$.