Waves
What is phase difference and what is it measured in?
How much a wave lags behind another wave. Measured in radians
How is polarisation used un antennas?
TV and radio signals are polarised by the orientation of the rods. Ariel must be in the same plane as ghr signal
What is the phase difference of two waves completely out of phase
pi
In the fringe spacing formula what letter means what
w= Distance between fringes
D = distance from slit to screen
S = distance between centre of thr slits
In an optical fibre, what happens if the angle of incidence is greater than the critical angle?
Total internal reflection
What is modal dispersion? And how do we stop it?
When the light takes multiple paths and causes the signal to elongate. Using a filter or use a thin fibre so the sources cannot spread out
What is material diSpersion and how do we stop it?
Different wavelegnths travel at different speeds. Use light of all the same wavelength