Question

The wavelength of violet light is 4.0 x 10^−7 m. The wavelength of red light is 6.5 x 10^−7 m. How much longer is the wavelength of red than violet?

A 2.5 × 10^–7 m
B 1.05 × 10^–7 m
C 2.5 × 10^–6 m
D 1.05 × 10^–6 m

Answer 1

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