In an interference experiment using a monochromatic source emitting light of wavelength 2, the fringes are produced by two long, narrow slits separated by a distance d. The fringes are formed on a screen which is situated at a distance D >> d.Write down an expression for the fringe width w. Please use "*" for products (e.g. B*A), "/" for ratios (e.g. B/A) and the usual "+" and "-" signs as appropriate. Use "lambda" (without the quotes) for å in the equation box. For example, use d*lambda for d2. Please use the "Display response" button to check you entered the answer you expect.

In an interference experiment using a monochromatic source emitting light of wavelength 2, the fringes are produced by two long, narrow slits separated by a distance d. The fringes are formed on a screen which is situated at a distance D >> d.Write down an expression for the fringe width w. Please use "" for products (e.g. BA), "/" for ratios (e.g. B/A) and the usual "+" and "-" signs as appropriate. Use "lambda" (without the quotes) for å in the equation box. For example, use d*lambda for d2. Please use the "Display response" button to check you entered the answer you expect.