Assertion : Television signals are received through sky-wave propagation. Reason : The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency.

Step-by-step solution

In sky wave propagation, the radio waves having frequency range 2 MHz to 30 MHz are reflected back by the ionosphere. Radio waves having frequency nearly greater than 30 MHz penetrates the ionosphere and is not reflected back by the ionosphere. The TV signal having frequency greater than 30 MHz therefore cannot be propagated through sky wave propagation. In case of sky wave propagation, critical frequency is defined as the highest frequency that is returned to the earth by the considered layer of the ionosphere aft