Question

The frequency of the electromagnetic wave, which best suited to observe a particle of the size $3\times {10}^{-6}\text{m}$ is of the order of:

• A. ${10}^{14}\text{Hz}$
• B. ${10}^{15}\text{Hz}$
• C. $2\times {10}^{13}\text{Hz}$
• D. $3\times {10}^{15}\text{Hz}$

Answer 1

Answer: (A)

${10}^{14}\text{Hz}$

The particle can be observed when the wavelength of light used is of the order of its size. Therefore, the required frequency

$V=\frac{C}{\lambda }=\frac{C}{\text{Size of object}}=\frac{3\times {10}^8}{3\times {10}^{-6}}={10}^{14}Hz$