______ is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.

• antenna

• circuits

• amplifier

• mutliplier

In radiation pattern, field intensity decreases with increasing distance as,

• 1/r

• 2r

• r/4

• r x r

In radiation pattern, pattern independent on _______

• shape

• distance

• voltage

• current

For Isotropic antenna, the value of beam area and directivity is

• 4pi and 1

• 2pi and -1

• 4pi and -1

• 2pi and 1

For isotropic antenna, the value of efficiency factor is between

• -1 < k < 1

• 0 < k < 1

• k = 1

• k = 0

Gain is lower than Directivity is due to ______

• energy losses

• Ohmic losses

• scattering loss

• lossless medium

Poynting vector is defined as

• power flow per unit area

• current flow per unit potential

• point per unit differential area

• potential per unit differential area

Power density at any distance from an isotropic antenna is simply the transmitted power dived by the _______ at that distance.

• area of square

• area of rectangle

• area of circle

• area of sphere

In Isotropic Antenna, if the radiated power is calculated by taking half-wave dipole as the reference, ______

• Effective Aperture

• Effective Radiated Power

• Power density

• Radiation Intensity

The amount of power that an isotropical antenna radiated to produce the peak power density observed in the direction of maximum antenna gain, _____

• EIRP

• ERP

• Peak Gain

• Directivity