A) λ = 548 nm.
B ) 5.474 x 10¹⁴ Hz.
Explanation:
Distance between two slits ( d ) =.044 x 10⁻³
Distance of screen ( D ) = 6.5 m
Fringe width is given by the expression
Fringe width = λ D /d
where λ is wave length of light .
Given fringe width = 8.1 cm
Putting the values in the equation , we have
8.1 x 10⁻² = λ x 6.5 / .044 x 10⁻³
λ = 548 nm.
Frequency of light = velocity of light / wavelength
3 x 10⁸ / 548 x 10⁻⁹
= 5.474 x 10¹⁴ Hz.
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