In free space, an electromagnetic wave of 3 GHz frequency strikes over the edge of an object of size (λ)/(100), where λ is the wavelength of the wave in free space. The phenomenon, which happens there will be: (a) Reflection (b) Refraction (c) Diffraction (d) Scattering

Answer: (d). λ = c/ν = (3×10⁸)/(3×10⁹) = 0.1 m. Object size = (λ)/(100) = 1 mm, much smaller than λ. When the obstacle is much smaller than the wavelength, the wave is scattered (diffraction needs size comparable to λ). So the answer is (d) Scattering.

In free space, an electromagnetic wave of 3 GHz frequency strikes… | JEE Main 2022 (26 Jun, Shift 1)

Q15JEE Main 2022 · 26 JUN · SHIFT 1Easy

Electromagnetic Spectrum & Atmosphere

In free space, an electromagnetic wave of 3 GHz frequency strikes over the edge of an object of size $\frac{\lambda}{100}$ , where $\lambda$ is the wavelength of the wave in free space. The phenomenon, which happens there will be:

Show answer and solution

Answer: (d)

$\lambda = \dfrac{c}{\nu} = \dfrac{3\times10^8}{3\times10^9} = 0.1\ \text{m}$ .
Object size $= \dfrac{\lambda}{100} = 1\ \text{mm}$ , much smaller than $\lambda$ .
When the obstacle is much smaller than the wavelength, the wave is scattered (diffraction needs size comparable to $\lambda$ ).
So the answer is (d) Scattering.

Report a mistake

Electromagnetic Spectrum & Atmosphere question from JEE Main 2022 (26 Jun, Shift 1)

More questions on Electromagnetic Spectrum & Atmosphere