T4.3 Wave characteristics

Question 1

Amplitude (A)

Answer 1

For mechanical waves: Amplitude is the maximum displacement from the mean position. Amplitude will remain constant if the wave does not lose any of its energy (undamped oscillation).

Question 2

Intensity (I)

Answer 2

The intensity of a wave is the power per unit area that is received by the observer. The units are W m^-2. The intensity of a wave is proportional to the square of its amplitude: I∝A^2

Question 3

Superposition

Answer 3

When two waves of the same type (same frequency/wavelength; the same or similar amplitude) meet (in space and time) and interfere.

Question 4

Unpolarised light

Answer 4

Electric fields of unpolarised light, vibrate in all possible directions perpendicular to the direction of the wave energy propagation. Electric fields oscillates in all random directions.

Question 5

Polarised light

Answer 5

Only transverse waves can be polarised with a polarizer which is a device that only allows a specific orientation of the electric field to go through.

Question 6

Light can be polarized by…

Answer 6

1. Polaroid (polariser) (filter)
2. Reflection
3. Optically active solutions