engineering recuitment GATE ECE 2023-24 Test Series Electromagnetic Theory Waveguides and Guided Waves Optical Fiber
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 θc.
The value of d (in meter) is _________.
Enter numerical value using the virtual keypad. Round off where necessary.