1. Capacitance T.T. The Professional Development Service for Teachers is funded by the Department of Education and Skills under the National Development Plan

2. + + + + + + + + - - - - - - - - Capacitance The Capacitance of a body is defined as the ratio of the charge (Q) on the body to its potential (V): Q = charge V = potential A capacitor is device used to store energy. Two metal plates facing each other increases the charge that each can store. PDST Resources for Leaving Certificate Physics2

3. Capacitor + + + + + + + + - - - - - - - - capacitance of a capacitor energy stored in a capacitor See demonstration experiments PDST Resources for Leaving Certificate Physics3

4. Describe an experiment to demonstrate that a capacitor can store energy. (12) + + + + + + + + - - - - - - - - capacitor To demonstrate that a capacitor stores energy Van De Graaf bulb • Method: • Set up the apparatus as shown. • Allow the capacitor to build up a charge. • Disconnect it from the generator • Bring a conducting wire from each plate to the bulb Observation: The bulb flashes Conclusion: The presence of light energy indicates that energy had been stored on the capacitor PDST Resources for Leaving Certificate Physics4