Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202528 JanuaryEvening Shift
Exam
JEE Main
Year
2025
Date
28 January
Shift
Evening Shift
Subject
Physics
Chapter
Capacitance

JEE Main 2025 · 28 January · Evening Shift · Physics · Capacitance

A parallel plate capacitor of capacitance 1 μ ~F is charged to a...

A parallel plate capacitor of capacitance 1μ F1 \mu \mathrm{~F} is charged to a potential difference of 20 V . The distance between plates is 1μ m1 \mu \mathrm{~m}. The energy density between plates of capacitor is.

Options

  1. A2×10−4 J/m32 \times 10^{-4} \mathrm{~J} / \mathrm{m}^3
  2. B1.8×105 J/m31.8 \times 10^5 \mathrm{~J} / \mathrm{m}^3
  3. C1.8×103 J/m31.8 \times 10^3 \mathrm{~J} / \mathrm{m}^3
  4. D2×102 J/m32 \times 10^2 \mathrm{~J} / \mathrm{m}^3

Correct answer

C. 1.8×103 J/m31.8 \times 10^3 \mathrm{~J} / \mathrm{m}^3

Step-by-step solution

 Energy density =12ε0E2=12ε0(Vd)2=12(8.85×10−12)(2010−6)2J/m3≃1.8×103J/m3\begin{aligned} \text{ Energy density } & =\frac{1}{2} \varepsilon_0 E^2 \\ & =\frac{1}{2} \varepsilon_0\left(\frac{V}{d}\right)^2 \\ & =\frac{1}{2}\left(8.85 \times 10^{-12}\right)\left(\frac{20}{10^{-6}}\right)^2 \mathrm{ J} / \mathrm{m}^3 \\ & \simeq 1.8 \times 10^3 \mathrm{ J} / \mathrm{m}^3\end{aligned}
Practice Capacitance on Quantrex Academy →

More from Capacitance

Passage: A container of height 2 m, length 2 m and breadth 1 m is made of insulating… JEE Advanced 2026A parallel plate capacitor is having separation between plates 0.885 mm. It has a… JEE Main 2026A sphere of capacitance 100 pF is charged to a potential of 100 V. Another identical… JEE Main 2026From the circuit given below, the capacitance between terminals A and B shown in the… JEE Main 2026A parallel plate air capacitor is connected to a battery. The plates are pulled apart at… JEE Main 2026Consider a circuit consisting of a capacitor ( 20\ μ F), resistor ( 100\ Ω ) and two… JEE Main 2026The dimensional formula of (1)/(2)ε_0 E^2 ( ε_0 = permittivity of vacuum and E = electric… JEE Main 2026A parallel plate air capacitor has a capacitance C . When it is half filled as show in… JEE Main 2026 Full Capacitance list All JEE Main PYQs