The limits of the visible spectrum are 4000Å to 7000Å. Show that the violet of the thrid order visible spectrum overlaps the red of the second order spectrum produced by a plane diffraction grating having 15,000 lines per inch, when visible light is incident normally on the granting.

A plane transmissio grating when illuminated with normal light produces a second order diffraction at 30^(@) for wavelength lamda =500 Å. Calculate the number of lines per cm on the grating.

In a spectrometer experiment, monochromatic light is incident normally on a diffraction grating having 4.5xx10^5 lines per metre. The seond order line is seen at an angle of 30^@ to the normal. What is the wavelength of the light?

Select the appropriate options and complete the following paragraph. (spectrum, dispersion, grey, green, maximum, minimum, electromagnetic, refraction, optical, intense) Light is an ___ radiation. The process of separation of light into its component colours while passing through a medium is called as of light. The band of coloured components of a sunlight beam is called its ___ Various colours appearing in the spectrum are of the order as violet, indigo, blue, yellow, orange and red. Different colours have different wavelengths which are visible to our eyes i.e., between 400 nm and 700 nm. Red light has ____ wavelength whereas violet light has ____ wavelength.

A thin film having refractive index mu" = 1.5" has air on both sides. It is illuminated by white light falling normally on it. Analysis of the reflected light shows that the wavelengths 450 nm and 540 nm are the only missing wavelengths in the visible portion of the spectrum. Assume that visible range is 400 nm to 780 nm. (a) Find thickness of the film. (b) Which wavelengths are brightest in the interference pattern of the reflected light?

Statement I: A beam of white light enters the curved surface of a semicircular piece of glass along the normal. The imcoming beam is moved clockwise (so that the angle theta increases), such that the beam always enters along th enormal to the curved side. Just before the refracted beam disappears, it becomes predominantly red. Statement II: The index of refraction for light at the red end of the visible spectrum is more than at the violet end.

All bodies, no matter how hot or cold, continuously radiate photons. At a given temperature, the intensities of the electromagnetic waves emitted by an object vary from wavelength to wavelength throughout the visible, infrared, and other regions of the spectrum. Figure illustrates how the intensity per unit wavelength depends on wavelength for a perfect blackbody emitter. Although this figure can strictly be applied only to a black body, yet this will approximately discribe the behavior of many of the self radiating systems. For example, sun has an approximate temperature of 6000K. it is not a black body, it has an emissivity of nearly 0.6 But its peak almost occurs at a wave length that predicted by Wein's law. Suppose we have a bulb of power 100W. It emits only about 5W as visible light, rest is emitted as infrared radiated. Assume that the bulb filament has a surface area of 10mm^(2) (hc=1250 eV-nm) Assume that the light emitted by the bulb in the visible region is entirely of wavelength 500 nm. What is the number of photons emitted per second in the visible region?