Answer :

(i) Sky wave propagation is used by short wave broadcast services having frequency range from a few MHz up to 30 MHz.


(iii) The sky waves suffer reflection in the ionosphere and reach the receiver after reflection. The oscillating electric field of electromagnetic wave provides the electrons in the ionosphere with energy and thus, change the velocity of the electrons which in turn affects the effective dielectric constant and hence refractive index. Radio-waves cover a distance of not less than 4000 km after reflection from the ionosphere . In this way, a very long distance communication is possible with the help of sky waves.

(ii) There is an upper limit to frequency of waves used in this mode because the waves which are above the frequency of 40 MHz are refracted through ionosphere and escape.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses

(i) Identify the Physics - Board Papers

(i) Which mode ofPhysics - Board Papers

The maximum frequPhysics - Exemplar

Figure 15.3 showsPhysics - Exemplar

Why a signal tranPhysics - Board Papers

A 50 MHz sky wavePhysics - Exemplar

(i) The intensityPhysics - Exemplar

If the whole eartPhysics - Exemplar