A parallel plate capacitor is charged by a dc source to potential V.Without disconnecting the capacitor form the source,air is replaced by another dielectric medium of dielectric constant 10.State with reasons how

1)electric field between the plates

2)energy stored in the cpacitor change

1. In present case, the air is replaced by another dielectric medium of dielectric constant 10 without disconnecting the capacitor from the d.c source, hence potential difference between the plates of capacitor remains unchanged. Consequently, electric field between the plates remains unchanged.

2. Now capacitance of capacitor C_m = K C = 10 C

Thus, energy stored becomes 10 times the value with air as dielectric.