Question

Question 24 (1 point) In thin film problems, the condition for bright reflection when 1 wave (only is phase shifted becomes 2t = (m +1/2)40/n 2t =mo 2t = (m +1/2)0 none of these 2t = m/o/n Question 25 (1 point) ✓ Saved

Answer 1

Option 1 is correct
A no s all not oil, n=105 Wath, nal.3} 2 Well as 4 2. & is phase shift • Lets take an example of reflection from this filme of oil of thickness it and refractive index n. assume that light is falling nor normally angle of incidence angle of reflection is zero Now light reflecting from air-coil intoface sitter a phase change of 180° with respect to incident light. A 180° s phase shift is equal to light having travelled distance of I wavelength, no But, tight reflecting from oil wou inteftace will have bhase shift as there light travelling from denser to rare medium. thie a 2 no

ul a for the light reflected off the oil and light reflected off wath ito "isterfere constructirely need total phase shift of 360°. This happens if thickness , ut of film is equal to etc 1 1 do 3 dor 5 do 4 ų Therefore condition for bright refletion will be, It = (m+tan m=0,12 9 4 ana wavelength of light in oil (filin) ui do n 6 Where To z wavelength of light û all SUNDAY 06 na refractive index of oil (thin fitur) so, at z ( mt 1 2 Z n