An antenna is mounted on a 400 m tall building. What will be the wavelength of signal that can be radiated effectively by the transmission tower upto a range of 44 km?

A transmitting antenna at top of a tower has a height of 50 m and the height of receiving antenna is 80 m. What is range of communication for Line of Sight (LoS) mode?

[use radius of earth = 6400 km]

In amplitude modulation, the message signal

V_m(t) = 10 sin (2$$\pi$$ $$\times$$ 10⁵t) volts and

Carrier signal

V_C(t) = 20 sin(2$$\pi$$ $$\times$$ 10⁷ t) volts

The modulated signal now contains the message signal with lower side band and upper side band frequency, therefore the bandwidth of modulated signal is $$\alpha$$ kHz. The value of $$\alpha$$ is :