A parallel plate capacitor of capacitance 90 pF is connected to a battery of emf 20 V. If a dielectric material of dielectric constant `K =(5)/(3)` is inserted between the plates the magnitude of the charge will be :

Options

A. `1.2 ` nC
B. `0.3` n C
C. `2.4 ` n C
D. `0.9` n C

Answer

A, B, C

Explanation

Q = K C V
`= (5)/(3) xx90 xx10^(-12) xx20`
`3000xx10^(-12)C = 3 n C `

Current induced in dielectric
`Q - Q (1- (1)/(K))`
`= 3 n C (1-(1)/(5//3))`
`= 3 (1-(3)/(5))n C `
`= 3xx(2)/(5) n C = 1.2 n C `