Question

The expression for refractivity in terms of the Pressure and temperature coefficient is given by ____________

(a) \(\frac{77.6}{T}P+4810 \frac{e}{T} \)

(b) \(\frac{77.6}{P}T+4810 \frac{e}{T} \)

(c) \(\frac{77.6}{P}T+4810 \frac{T}{e} \)

(d) \(\frac{77.6}{T}P+4810 \frac{T}{e} \)

This question was addressed to me during an interview.

The doubt is from Space Wave Propagation topic in chapter Space Wave Propagation of Antennas

Answer 1

Right choice is (a) \(\frac{77.6}{T}P+4810 \frac{e}{T} \)

Explanation: The expression used to calculate refractivity is given by

\(N=\frac{77.6}{T} P+4810 \frac{e}{T} \)

Where p is the total pressure in millibars, e is the partial pressure of water vapor and T is the absolute temperature.