General Studies I
Each of the following 3 questions consists of two statemetns, one labelled as ‘Assertion (A)’ and the other as ‘Reason (R)’. You are to examine these two statements carefully and select the answers to these items using the code given below.
Reason (R): Radio waves are electromagnetic in nature Code:
Assertion (A): Radio waves bend in a magnetic field
A both A and R are individually true and R is the correct explanation of A B Both A and R are individually true but R is not the correct explanation of A C A is true but R is false D A is false but R is true
Reason (R): Radio waves are electromagnetic in nature
Radio waves also bend. Recall our discussion that water absorbs and affects radio waves? Variations in water vapor in the air can bend radio waves and plays an important part in a phenomenon called tropo duct openings.
Normally, air temperature continuously decreases as one goes higher in the atmosphere. Occasionally, a weather phenomenon called a temperature inversion occurs that traps a pocket of warm air at higher altitudes. The warm air is sandwiched between two layers of cooler air.
Since warm air can hold more moisture, it has more water vapor than the surrounding cooler, dry air. Radio signals travel slower in the warm, moist air than in the cooler air. This causes the cool air to bend or refract radio signals towards the warmer air. In effect, the two layers of cool air now form a wave guide