A certain part of the electromagnetic spectrum ranges from $200 \mathrm {~nm}$ to $400 \mathrm {~nm}$. What is the lowest frequency associated with this portion of the spectrum? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$
A) $7.50 \times 10^{13} \mathrm {~Hz}$
B) $7.50 \times 10^{15} \mathrm {~Hz}$
C) $1.50 \times 10^{15} \mathrm {~Hz}$
D) $1.50 \times 10 ^ { 14 } \mathrm {~Hz}$
E) $7.50 \times 10 ^ { 14 } \mathrm {~Hz}$

Question

Quizplus · Accepted Answer

The lowest frequency corresponds to the longest wavelength, which is $400 \mathrm{~nm}$. Using the formula $f = \frac{c}{\lambda}$, where $c = 3.00 \times 10^8 \mathrm{~m/s}$ and $\lambda = 400 \times 10^{-9} \mathrm{~m}$, the frequency is $7.50 \times 10^{14} \mathrm{~Hz}$.

A Certain Part of the Electromagnetic Spectrum Ranges From 200 nm200 \mathrm {~nm}200 nm

A Certain Part of the Electromagnetic Spectrum Ranges From $200 \mathrm {~nm}$