A speech signal given by 11 sin(2200 $$\pi$$t) V is used for amplitude modulation with a carrier signal given by 44 sin(6600 $$\pi$$t) V. The minimum amplitude of modulated wave will be :

The TV transmission tower at a particular station has a height of 125 m. For doubling the coverage of its range, the height of the tower should be increased by

Only 2% of the optical source frequency is the available channel bandwidth for an optical communicating system operating at 1000 nm. If an audio signal requires a bandwidth of 8 kHz, how many channels can be accommodated for transmission :

Amplitude modulated wave is represented by $${V_{AM}} = 10\,[1 + 0.4\cos (2\pi \times {10^4}t)]\cos (2\pi \times {10^7}t)$$. The total bandwidth of the amplitude modulated wave is :