In a parallel plate capacitor, each plate has an area of \( 7 \times 10^{-3}\,\mathrm{m^{2}} \) and the distance between the plates is 2 mm. The space between the plates of the capacitor is filled with mica having dielectric constant 6. If the capacitor is connected to 120 V supply, the charge on each plate of the capacitor will be (Given: permittivity of the vacuum \( = 8.85 \times 10^{-12} \) SI unit)
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \( 2.23 \times 10^{-8}\,\mathrm{C} \)
The capacitance of a parallel plate capacitor filled with a dielectric of constant \( K \) is \( C = K\varepsilon_0 A/d \), and the charge on each plate is \( Q = CV \).
\( A = 7\times10^{-3}\,\mathrm{m^{2}} \)
\( d = 2\,\mathrm{mm} = 2\times10^{-3}\,\mathrm{m} \)
\( \displaystyle C = \frac{6 \times 8.85\times10^{-12} \times 7\times10^{-3}}{2\times10^{-3}} = 1.86\times10^{-10}\,\mathrm{F} \)
\( \displaystyle Q = CV = 1.86\times10^{-10} \times 120 = 2.23\times10^{-8}\,\mathrm{C} \)
Note: NTA picked this question from an NCERT (2026-27) exercise and changed the figures. Do not ignore NCERT while practising numericals.
NCERT (2026-27):
Exercises – …
