(b) Two charges of magnitude 0.610 £gC and 0.490 £gC are in a liquid dielectric with dielectric constant £e = 45.0. The charges are separated by a distance of 0.290 m.

(i) What is the size of the electric force between the charges?

(ii) By how many times is the electric force between the charges weaker in the dielectric than it would be if the particles were in a vacuum (£e = 1.00)?

V

(ii) The circuit is then left for a long time with the switch closed so that the capacitor fully charges to 30.0 V. The switch is now carefully opened so that no charge leaves the capacitor and the battery is also replaced by a resistor of resistance 160. k£[.

What will be the voltage across the capacitor 160. s after the switch is closed again?