7. The heating element of a toaster has resistance 85 , and is connected to a voltage source with peak-to-peak voltage of 625 V. Calculate the average power dissipated by the toaster. [2 marks]
8. A polariser is being used to block a polarised laser beam, but 5% of the light is still being transmitted. Calculate how much the polariser needs to be rotated from its current position to completely block the laser light. [2 marks]
9. Light travelling from water into glass has an incident angle of 20 and a refracted angle of 16 Calculate the refractive index of the glass [2 marks]