A capacitor of capacitance 15 nF having dielectirc slab of `epsilon_(r)=2.5` dielectric strength 30 MV/m and potential difference = 30 volt. Calculate the area of plate

Options

A. `6.7xx10^(-4)m^(2)`
B. `4.2xx10^(-4)m^(2)`
C. `8.0xx10^(-4)m^(2)`
D. `9.85xx10^(-4)m^(2)`

Answer

A

Explanation

`C=(A epsilon_(0) epsilon_(r))/(d)`
`rArr 15 xx 10^(-9) = (A xx 8.85 xx 10^(-12) xx 2.5)/( d) " " ` …(i)
Since, `E=(V)/(d)`
`rArr 30 xx 10^(6)=(30)/(d)`
`d=10^(-6)m`
from (i)
`15 xx 10^(-9) =(A xx 8.85 xx 10^(-12) xx 2.5)/( 10^(-6))`
`A=(15 xx 10^(-9)xx10^(-6))/(8.85 xx 10^(-12) xx 2.5) `
`=6.7 xx 10^(-4)m^(2)`