15 - Optics Questions Answers
IN D QUES OF RED ROSE IN WHICH WE HAVE TO FIND COLOR WHY THE COMPLEMENT COLOR OF BLUE i.e ORANGE &RED WILL B SEEN
since only blue light is present so any other colour can not be the answer
A RED ROSE IS KEPT IN BLUE LIGHT. WHAT COLOUR OF ROSE WILL BE SEEN?
Since it is red rose it means it will absorb all colours other than red so in blue light it will be seen as black.
A transparent sheet of paper of refractive index 'n' and thickness 't' is pasted on one of the slits in YDSE which uses monochromatic light of wavelength 'x' . How many fringes will cross through the centre if the paper is removed ?
total path difference created by the paper = (n-1)t
geometrical path difference = yd/D
so position of central maxima will be obtained by eq. (n-1)t = yd/D
here y is position of central bright, d is slit appeture and D is distance between slits and screen.
so y = (n-1)tD/d
width of maxima = xD/d , x is wavelength of light
so no. of fringes shifted = [(n-1)tD/d]/[xD/d] = (n-1)t/x
what is meant by rate of change of transverse magnification
transverse magnification m = v/u so rate of change of trasverse magnification is dm/dt. calculate by differentiation
Focsl length of lens depends on colour of light?
Yes, f depends on µ and µ depends on colour of light