Optics Answers

 A diffraction grating produces a second-order principal maximum at 50.6° to the normal when being illuminated normally with light of wavelength 644nm. Calculate the number of lines per millimeter of the grating and the total number of principal maxima produced.

          A diffraction grating has 1.2 × 10⁴ rulings or lines uniformly spaced over a width w = 25.4mm. This grating is illuminated at normal incidence by yellow light from a sodium vapour lamp of wavelength 589nm. Determine the greatest angle at which an order can occur on either side of the center of the diffraction pattern?

          A plane diffraction grating is illuminated by a source that emits two spectral lines of wavelengths 420nm and 600nm. Show that the 3rd order of the line of one of these wavelengths is diffracted through a greater a greater angle than the 4th order of the other wavelength.

A screen is placed at a distance of 100𝑐𝑚 from a circular hole illuminated 

by a parallel beam of light of wavelength 6400Å. Compute the radius of 

fourth half period zone.

Write another form of bragg law

Explain bragg equation of diffraction.

A final linear velocity of Com for a sphere is found to be x wr, when it is mode to fall on a surface (coefficient of friction r). Initially the sphere was rotating with an angular velocity of w about its own horizontal axis The instance it is mode to fall on the surface, it begins to stand first and then starts rotating without standing. (a) Find the value of x? (b) Distance covered before reacting their final linear velocity is y = r²omega²/meuo x g  Find the value of y 

A Plane mirror is placed on the other side of a cover lens having a focal length of 12 cm. A distinct image is formed in front of the lens (towards the object) when the plane mirror is at a distance of 45 cm from the lens, Calculate the distance of image from the lens. 

A 2.00m long wire having a mass of 0.100kg is fixed at both ends. The tension in the wire is maintained at 20.0N 

1. What are the frequencies of the first three allowed modes of vibration? 
2. If a node is observed at a point 0,400m from one end, in what mode with what frequency is it vibrating? 

A string is 0,400m long and has a mass per unit length of 9.00 x 10^-3 kg/m. What must be the tension in the string if it’s second harmonic has the same frequency as the second resonance mode of a 1.75m long pipe open at one end?