2.1 (j)
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Demonstration 1
By this point, you have probably already shown the Young's Slits demonstration with a laser and used the equation seveal times. It may be an opportune moment to derrive the expression, hence doing 2.1 (n) at this point. It is worth telling the pupils that this equation can only be used for small angles and hence with the microwave kit it is only reliable to work out positions of maxima and minima using path differrence.