`C,Q,V` and `U` are capacitance, charge, potential difference and energy stored in an isolated parallel `1` plate capacitor respectively. Now a dielectric slab is placed between plates of capacitor, the quantities that decreases

Options

A. `C,Q`
B. `C,V`
C. `V,U`
D. `Q,U`

Answer

C

Explanation

Since capacitor is isolated, its charge remains same.
`Q'=Q,C'=KC,C' gt C`
`Q'=QimpliesC'V'=CVimpliesKCV'=CVimpliesV'=(V)/(K),V' lt V`
`U=(Q^(2))/(2C), U'=(Q^(2))/(2C')=(Q^(2))/(2KC)impliesU' lt U`