The frequency of EM wave which is best suited to observe a particle of radius 3 × 10-4 cm is of the order

Q: The frequency of EM wave which is best suited to observe a particle of radius 3 × 10^-4 cm is of the order

(a) 10¹⁵

(b) 10¹⁴

(c) 10¹³

(d) 10¹²

Sol: If λ be the radius of  the particle then λ = 3 × 10^-6  m

Frequency of EM wave , $\large \nu = \frac{c}{\lambda} $

$\large \nu = \frac{3 \times 10^8}{3 \times 10^{-6}} = 10^{14} $

Thus to observe the particle , the frequency of wave should be more than 10¹⁴ Hz i.e. 10¹⁵ Hz or smaller value of wavelength .