Audio sine waves of 3 kHz frequency are used to amplitude modulate a carrier signal of 1.5 MHz . Which of the following statements are true?
A TV transmission tower has a height of 240 m . Signals broadcast from this tower will be received by LOS communication at a distance of (assume the radius of earth to be $\left(6.4 \times 10^6 \mathrm{~m}\right)$
The frequency response curve (figure) for the filter circuit used for production of AM wave should be
In amplitude modulation, the modulation index $m$, is kept less than or equal to 1 because
Which of the following would produce analog signals and which would produce digital signals?
(a) A vibrating tuning fork
(b) Musical sound due to a vibrating sitar string
(c) Light pulse
(d) Output of NAND gate
Analog and digital signals are used to transmit information, usually through electric signals. In both these technologies, the information such as any audio or video is transformed into electric signals.
The difference between analog and digital technologies is that in analog technology, information is translated into electric pulses of varying amplitude. In digital technology, translation of information is into binary formal (zero or one) where each bit is representative of two distinct amplitudes.
Thus, (a) and (b) would produce analog signal and (c) and (d) would produce digital signals.