1. Capacitance Physics Department, New York City College of Technology

2. Key words Capacitor Capacitance Parallel-plate capacitor

3. Capacitor A device that can store electric charge

4. Capacitance For a given capacitor, we find Q is the amount of charge acquired by each conducting plate of the capacitor V is the voltage applied across it C is called capacitance

5. Capacitance The unit of capacitance is farad (F) C does not depend on Q or V Instead, C depends on Size Shape Relative position of the two conductors The insulating material between them

6. Parallel-plate capacitor Plate area A Plate separation d Permittivity of the insulating material ε Dielectric constant k with Capacitance C

7. Energy stored in a capacitor The electric potential energy stored in a capacitor is Since, we have

8. Example #1 capacitor