Q. Two parallel plates have equal and opposite charge. When the space between them is evacuated, the electric field between the plates is $2 \times 10^{5}\ V/m.$ When the space is filled with dielectric, the electric field becomes $1 \times 10^{5}\ V/m$. The dielectric constant of the dielectric material
A) 1/2
B) $1$
C) $2$
D) $3$
Explanation
(c) $K = \frac{E_{without\ dielectric}}{E_{with\ dielectric}} = \ \frac{2 \times 10^{5}}{1 \times 10^{5}} = 2$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.