Question 61. A medium of relative permittivity εr2 = 2 forms an interface with free space. A point source of EM energy is located in the medium at a depth of 1 meter from the interface. Due to the total internal reflection, the transmitted beam has a circular cross-section over the interface. The area of the beam cross section at the interface is given by

Question 62. The current distribution of a half wave dipole is

Question 63. For the same length of arrays, half power beam-width of binomial array

Question 64. The effective electrical length of an antenna is __________ its physical length

Question 65. Cassergain feed is used with a parabolic reflector to

Question 66. The direction in a Yagi Uda antenna is longer than the radiating element.

Question 67. The relative permeability is taken as unity for which of the following?

Question 68. Which of the following term applies to troposcatter propagation?

Question 69. Maximum effective aperture of a λ/2 antenna is

Question 70. The disturbance from adjacent power lines is known as