Answer:
200 nm is the thinnest film that produces a strong reflection for green light with a wavelength of 500 nm
Explanation:
If two reflected waves interfere constructively ,strong reflection is produced. Two reflected waves will experience a phase change
For constructive interference

for thinnest film m=1
refractive index should be taken for film n=1.25
thickness of the thinnest film is

Answer:
Explanation:
In Michelson interferometer , two light waves from different directions are made to overlap so that fringes are formed on the screen due to interference . In it, two monochromatic and coherent light are made to overlap which have some path difference or phase difference. They form dark and bright fringes .
Now when a match stick is lit in the path of a wave , the fringes will disappear and an general illumination will be observed on the screen as the light from the lit match stick will not be coherent . Incoherent light can not form stable fringes.
Answer:
Magnetic field can be used to produce current, infact a changing magnetic field can produce current.
A changing magnetic field in a loop causes the flux linked with the loop to change in turn generating a emf in the loop and therefore a current.
For a loop of area A and resistance R.
I =dPhi/dt/R
В. А
I = AcosФ/R .dB /dt
But it isn't reasonable to say that we can create a magnetic field by having a flow of current and this can be used to make more current because the current generated due to change in magnetic field created by increase/decrease in flow of current will be in a direction such that it will counter act the change in magnetic field caused by increase/decrease in current flow.(lenz's law).
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Ф= В. А
I = Acos dB Rd
<span>from a trough to the rest position and from a crest to the rest position.
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Answer:
warmer air
Explanation:
the particles are more excited which increases the probability that the particles will bump into each other