Complete the following sentences by circling the correct word:
The higher the frequency of an oscillation, the longer / shorter the wavelength and the closer / furtherapart the wavefronts are to / from one another.
The lower the frequency of the oscillation, the longer / shorter the wavelength and the closer / further apart the wavefronts are to / from one another.
Two students are investigating the relationship between intensity and amplitude. The graphs below show the variation of the displacement of a particle with time when two progressive waves X and Y pass separately through a medium.
The intensity of wave X is I0. Student 1 says that the intensity of wave Y must be but Student 2 thinks it must be .
(d)
Determine, using the relationship from part (c), which student is correct.
Unpolarised light with intensity I0 = 20 W m−2 is incident on the polariser. The analyser is rotated so that the transmission axis is at an angle of 35° compared to the vertical axis of the polariser.
Polaroid sunglasses use polarisation to reduce glare.
(d)
Choose suitable words and phrases to complete the following passage:
When unpolarised light is reflected / refracted from smooth non-metallic surfaces, partial / total plane polarisation occurs. Light is then polarised in a plane perpendicular / parallel to that surface.
Most surfaces around us are horizontal, therefore, most of the reflected / refracted light is polarised in the vertical / horizontal plane.
Polaroid sunglasses have a vertical transmission axis, which means that only light oscillating in the vertical / horizontal plane will be transmitted.
This greatly reduces the glare from reflective / refractive surfaces, such as water, allowing the wearer to see objects beneath the surface of the water more clearly.