Will the focal length of a lens for red light be more, same or less than that for blue light ?
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From lens maker's formula `(1)/(f) = (mu - 1)((1)/(R_(1)) - (1)/(R_(2)))` As `mu_(b) gt mu_(r ) :. F_(b) lt f_(r) or f_(r) gt f_(b)` i.e., focal length of a lens for red light will be more than the focal length of lens for blue light.
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Wavelength of orange light is greater than that of blue light.
If the focal length of a double convex lens for red light is f_(R) its focal length for the violet light is
The wavelength of orange light is greater than that of blue light . True/False
Assertion : The focal length of the lens does not change when red light is replaced by blue light. Reason : The focal length of lens does not depends on colour of light used.
Assertion : The focal length of lens does not change when red light is replaced by blue light. Reason : The focal length of lens does not depends on colour of light used.
If f(V) and f_(R) are the focal lengths of a concex lens for violet and red light respectively and F_(V) and F_(R) are the focal lengths of concave lens for violet and red light respectively, then we have
