Optics Answers

A plano-convex lens of radius 1.0 m is placed on an optically flat glass plate and is illuminated by an extended monochromatic source. Assume that the point of contact is perfect. The diameters of the 15th and 5th dark rings in the reflected light are 5.90X 10^-3 m and 3.36X10^-3 m Next, the space between the lens and the glass plate is filled with a liquid. The diameter of the 5th ring changes to 3.0X10^-3 m.Calculate the refractive index of the liquid when the ring is (i) dark, and (ii) bright, if the wavelength of light is 589 nm

A double slit interference pattern is produced by a parallel beam of light passing
through two slits of unequal widths 20 λ and 40 λ, respectively, where λ is the
wavelength of the light used. The distance between the centres of the slits is
1,000 λ. If the fringes are observed on a screen far off from the slits (D >> 1,000 λ),
calculate the separation of two adjacent maxima.

Two slits separated by a distance of 0.32mm. A beam of 500nm light strikes the slits producing an interference pattern. Determine the number of maxima observed in the angular interval -30°<x<30°

Two plano convex lens each of radius 100 are placed with their curved surfaces in contact with each other. Newton's rings are formed by a light of wavelength 6000A°. Find the distance between 10th and 20th fringe.

A ray of light is incident on an equilateral glass prism shows minimum deviation is 30°. Calculate the speed of light through prism?

In Newton's ring experiment the diameter of bright ring is reduced to 0.8 of its value after introducing a liquid below the convex surface.calculate the refractive index at liquid.

A double slit interference pattern is produced by a parallel beam of light passing through two slits of unequal widths 20 λ and 40 λ, respectively, where λ is the wavelength of the light used. The distance between the centres of the slits is 1,000 λ. If the fringes are observed on a screen far off from the slits (D >> 1,000 λ), calculate the separation of two adjacent maxima.

The electrical breakdown in air occurs at electric field strength of 3.5MV/m
.
Calculate the corresponding intensity of a plane wave.

A plane wave of wavelength 600 nm falls on a long narrow slit of width 0.6 mm.
(i) Calculate the angles of diffraction for the first two minima. (ii) How are these angles influenced if the width of slit is changed to 0.2 mm? (iii) If a convex lens of focal length 0.2 m is now placed after the slit, calculate the separation between the second minima on either side of the central maximum. (10)
b) For the arrangement described in above, repeat the calculations for the first two maxima on either side of the central maximum.

A Plano-convex lens of radius 1.0 m is placed on an optically flat glass plate and is illuminated by an extended monochromatic source. Assume that the point of contact is perfect. The diameters of the 15th and 5th dark rings in the reflected light are
5.90X10−3 m × and 3.36 X10−3 m. Next, the space between the lens and the glass plate is filled with a liquid. The diameter of the 5th ring changes to 3.0X10−3 m. Calculate the refractive index of the liquid when the ring is (i) dark, and (ii) bright, if the wavelength of light is 589 nm