Capacitance 0.0 / 5 ? PhysicsCapacitorsA2/A-levelCIE Created by: Dani10Created on: 01-12-15 13:23 Why is dielectric material used? 1) Increase the capacitance obtained from the given size capacitor. 2) Seperate the plates of capacitor and prevent them from touching. 1 of 7 How does a dielectric act? Reduces strength of the electric field between plates. When it is present the molecules are affected by electric field between the plates. 2 of 7 What happens if a dielectric is added to a capacitor which is connected to a battery? Extra charge to flow from the battery to maintain the p.d across the plates. Thus extra charge is stored. 3 of 7 Variation of capacitance with permittivity of dielectric? Capacitance is directly proportional to permittivity of dielectric. 4 of 7 What happens when switch is closed? It allows electrons to be drawn from +ve and deposited on the -ve plate. 5 of 7 Charging of a capacitor? When switch is first closed, no opposing potential, so large current and charge builds up rapidly on the capacitor. 6 of 7 Discharging of a capacitor? When switch is closed, electrons flow around the circuit from the -ve plate to +ve plate 7 of 7
Comments
No comments have yet been made