Question

The wavelength of red light is approximately 650 nanometres. This is equivalent to:

A) 650 000,000,000 m

B) 0.00000000065 m

C) 0.65 μm

D) 0.065 mm

Answer 1

$$650 \rm\: nm=650*10^{-9}\: m=0.650\:\mu m$$

Answer: C