Changing a Capacitor

Part of the Electricity and Magnetism section of Coddy's Physics journey. Lesson 19 of 51.

A dielectric between the plates multiplies the capacitance by κ:

$C = \kappa\,\varepsilon_0\,\frac{A}{d}$

A capacitor with a dielectric

Still connected to the battery: V stays the same. Disconnected: Q stays the same. Then use $Q = CV$ with the new C.

Challenge

A $2\ \mathrm{\mu F}$ capacitor is charged to $50\ \mathrm{V}$ and disconnected. Its plates are then pulled apart to twice the distance. What is its voltage $\relax V_{2}$ now?

Try it yourself

Solve for $V_{2}$

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Electricity and Magnetism

1Electric Charge and Force

Electric Charge Coulomb's Law Several Charges Recap - Charges in a Line

4Charged Conductors

The Charged Sphere Connecting Spheres Recap - Beam Between Plates

7Real Batteries

Internal Resistance The Variable Resistor Ammeters and Voltmeters Recap - Flashlight

10Magnetic Fields

Magnets and Magnetic Fields Field of a Wire Loops and Solenoids Recap - Electromagnet

2The Electric Field

The Electric Field Field of Several Charges The Uniform Field A Charge in a Uniform Field Recap - Stopping a Proton

5Capacitors

The Capacitor Combining CapacitorsChanging a CapacitorRecap - Camera Flash

8Kirchhoff's Laws

The Junction Rule The Loop Rule Solving Two Loops Recap - Charging a Battery

11Magnetic Forces

Force on a Moving Charge Circles in a Field Force on a Wire Two Parallel Wires Recap - Current Balance

3Energy and Potential

Electric Potential Energy Electric Potential Field and Potential Recap - Accelerating Ions

6Current and Resistance

Current and Voltage Resistance and Ohm's Law Series and Parallel Electric Power Recap - Fairy Lights

9Capacitors in Circuits

A Capacitor in a Circuit Charging a Capacitor Discharging a Capacitor Recap - Defibrillator

12Induction

A Rod Moving in a Field Magnetic Flux Faraday's Law Lenz's Law Recap - Generator