Question

10. In the middle of a calm lake, a radio receiver is installed on a pole at a height 4.0 m above water level. The receiver is used to track radio signals from a satellite orbiting the earth. As the satellite rises above the horizon, intensity of the signals at the receiver varies periodically. It is maximum, when the satellite is 30 above the horizon and then again when the satellite is 6° above the horizon. Wavelength of the satellite signals is closest to (a) 24 cm (b) 36 cm (c) 42 cm (d) 48 cm

C is ans

Answer 1

waves from um satellite from infinity The waves from Satellile can be consider as if they are coming Now this this problem can be modified to double slit interferance receiver lake pattern as shown modity Here o>>d, so Condition from maxima 个不 um d į dsin ona (d=8m) 个 um D u first occur at 0 - 30 & aa second ocQuy at 0=80, so 2 8 sin 30 nd a 8 sin 60 and also (n-n') = 1 so subnacting both, 1 = 8 (Sin 60-Sin 39 d=41.75cm ŭ 42cm . CS Scanned with CamScanner