Answer:
A 2.5 × 10^–7 m
Explanation:
Given
wavelength of violet light = 4.0 x 10^−7 m.
The wavelength of red light = 6.5 x 10^−7 m
To find the how much longer is wavelength of red light than violet light we have to find difference of wavelength of red and violet light
Difference in wavelength of red light and violet light =
wavelength of red light -wavelength of violet light
= 6.5 x 10^−7 m - 4.0 x 10^−7 m
Difference in wavelength of red light and violet light = (6.5 - 4.0)*10^−7 m
Difference in wavelength of red light and violet light =2.5 x 10^−7 m
Thus,
wavelength of red light is 2.5 x 10^−7 m longer than wavelength of violet light
option A