PYQs Based Test - 15 : Electromagnetics

Consider the 3 m long lossless air-filled transmission line shown in the figure. It has a characteristic impedance of 120π Ω, is terminated by a short circuit, and is excited with a frequency of 37.5 MHz. What is the nature of the input impedance (Zᵢₙ)?

The permittivity of water at optical frequencies is 1.75 ε₀. It is found that an isotropic light source at a distance d under water forms an illuminated circular area of radius 5 m, as shown in the figure. The critical angle is θ${}_c$.



The value of d (in meter) is _________.

The magnetic field of a uniform plane wave in vacuum is given by:

$\vec{H}\left(x,y,z,t\right)=\left({\hat{a}}_x+2{\hat{a}}_y+b{\hat{a}}_z\right)\cos \left(\omega t+3x-y-z\right)$

The value of b is

Two identical copper wires W1 and W2, placed in parallel as shown in the figure, carry currents I and 2I, respectively, in opposite directions. If the two wires are separated by a distance of 4r, then the magnitude of the magnetic field B between the wires at a distance r from W1 is

A microwave circuit consisting of lossless transmission lines T₁ and T₂is shown in the figure. The plot shows the magnitude of the input reflection coefficient Γ as a function of frequency 𝑓. The phase velocity of the signal in the transmission lines is 2 × 10⁸ m/s.



The length 𝐿 (in meters) of T₂ is ________