Question

A radio transmitting station operating at a frequency of 115 MHz has two identical antennas that radiate in phase. Antenna B is 8.95 m to the right of antenna A. Consider point P between the antennas and along the line connecting them, a horizontal distance x to the right of antenna A.

A) For what values of x will constructive interference occur at point P? Enter your answers in ascending order separated by a comma.

Answer 1

The frequency of the radio wave is 115MHz=115×10^6Hz

The velocity of a radio wave is 3×10^8m/sec

Velocity of a wave =frequency of the wave × wave length of the wave

3×10^8=115×10^6×wavelength of the wave

Wavelength of the wave =300/115~2.6m

The distance between the to radiating antenna is 8.95 m

Let the initial position of point p is at a distance x mts towards right of antenna A

8.95-2.6=6.35mts

6.25-2.6=3.75mts

3.75-2.6=1.15mts

So inorder to have a constructive iinterface between the to waves the point p should be at 1.15mts,3.75mts,6.35mts.