The electric field between the plates of a parallel plate capacitor is 'E'. If the charge on the plates is Q then the force on each plate is
Show Hint
- \(\text{QE}^2\)
- \(\text{QE}\)
- \(\frac{\text{QE}}{2}\)
- \(\frac{\text{QE}^2}{2}\)
The Correct Option is C
Solution and Explanation
Energy stored: $U = \tfrac12QV = \tfrac12QEd$.
Step 2: Force from energy:
At constant $Q$, force $= \dfrac{dU}{dd} = \dfrac12QE$.
Step 3: Result:
$F = \dfrac{QE}{2}$, option (C).
Final Answer:
The force on each plate is QE / 2. \[ \boxed{\text{(C) }\dfrac{QE}{2}} \]
Top Questions on Capacitors and Capacitance
- Energy stored in a capacitor is given by the equation \[ E = \frac{1}{2} C V^2 \] where: - \( C \) is the capacitance, - \( V \) is the voltage, - \( E \) is the energy stored. Given the values of \( C \), \( V \), and \( E \), determine the energy stored.}
- MHT CET - 2025
- Physics
- Capacitors and Capacitance
- Two capacitors $ C_1 = 4\mu F $ and $ C_2 = 6\mu F $ are connected in series across a 60 V battery. The potential difference across $ C_2 $ is:
- BITSAT - 2025
- Physics
- Capacitors and Capacitance
A circuit consisting of a capacitor C, a resistor of resistance R and an ideal battery of emf V, as shown in figure is known as RC series circuit.
As soon as the circuit is completed by closing key S₁ (keeping S₂ open) charges begin to flow between the capacitor plates and the battery terminals. The charge on the capacitor increases and consequently the potential difference Vc (= q/C) across the capacitor also increases with time. When this potential difference equals the potential difference across the battery, the capacitor is fully charged (Q = VC). During this process of charging, the charge q on the capacitor changes with time t as
\(q = Q[1 - e^{-t/RC}]\)
The charging current can be obtained by differentiating it and using
\(\frac{d}{dx} (e^{mx}) = me^{mx}\)
Consider the case when R = 20 kΩ, C = 500 μF and V = 10 V.- CBSE Class XII - 2025
- Physics
- Capacitors and Capacitance
- A parallel plate capacitor is charged by an ac source. Show that the sum of conduction current (\( I_c \)) and the displacement current (\( I_d \)) has the same value at all points of the circuit.
- CBSE Class XII - 2025
- Physics
- Capacitors and Capacitance
- Want to practice more? Try solving extra ecology questions todayView All Questions