Three capacitors `3muF, 6muF and 6muF` are connected in series to a source of 120 V. The potential difference, energy stored and charge of a parallel plate capacitor respectively. The quantities that increase when a dielectric slab is introduced between the plates without disconnecting the battery are

Options

A. 24
B. 30
C. 40
D. 60

Answer

D

Explanation

The combination of three charges in series
`(1)/(C)=(1)/(C_(1))+(1)/(C_(2))+(1)/(C_(3))=(1)/(3)+(1)/(6)+(1)/(6) rArr C=(6)/(4)=1.5muF`
The charge of this circuit, `q=CV=1.5xx120=180muC`
The potential difference across the `3muF`
`q=CVrArr V=(q)/(C)=(180)/(3)=60V`