Question

A `6xx10^(-4)` F parallel plate air capacitor is connected to a 500 V battery. When air is replaced by another dielectric material, `7.5xx10^(-4)`C charge flows into the capacitor. The value of the dielectric constant of the material is
A. `1.5`
B. `2.0`
C. `1.0025`
D. `3.5`

Answer 1

Correct Answer - C
`q_(0) = C_(0)V_(0)`
`q = CV_(0)`
`:. Deltaq = q - q_(0) = (C - C_(0))V_(0)`
or `Deltaq = (epsilon_(r)C_(0) - C_(0))V_(0) or Deltaq = (epsilon_(r) - 1)C_(0)V_(0)"......(i)"`
Here, `Deltaq = 7.5xx10^(-4)C`
`C_(0) = 6xx10^(-4)F`
`V_(0) = 500V`
Putting the value in Eq. (i), we get `(epsilon_(r) = 1.0025`