Plane polarised light of intensity $12{\mathrm{Wm}}^{-2}$ is incident at a Polaroid.

Calculate the intensity of the transmitted light when the angle between the plane of polarisation of the incident light and the transmission axis of the Polaroid is

(a) $45°$

Plane polarised light of intensity $12{\mathrm{Wm}}^{-2}$ is incident at a Polaroid.

Calculate the intensity of the transmitted light when the angle between the plane of polarisation of the incident light and the transmission axis of the Polaroid is

(b) $60°$.

This image shows the screen of an oscilloscope. The time-base of the oscilloscope is set at $500\mu s$, ${\mathrm{div}}^{-1}$ 

Calculate the time period of the signal and hence its frequency.

(a) State two main properties of electromagnetic waves.

(b) State one major difference between microwaves and radio waves.