GATE 2021: Communication System Rapid Quiz-1 (App update required to attempt this test)

When a sinusoidal message signal is applied to the X-plate of a CRO and the conesponding amplitude modulated signal is applied to the y-plates, the X-Y plot displayed on the screen of the CRO is as shown in the figure below.

The modulation index of the AM signal is equal to ______

What is the use of varacter diode in radio receiver?

A noise process has a power spectral density as shown.

The noise is passed through bandpass filter H(f) with bandwidth 4 MHz.

The output noise power will be ____ mW.

Four voice signals, each limited to 4 kHz and sampled at Nyquist rate are converted into binary PCM signal using 256 quantization levels. The bit transmission rate for the time-division multiplexed signal will be

Find the factor by which signal to quantization noise ratio will increase if number of bits in a PCM system is increased from n to n + 3.

A sinusoidal signal with peak-to-peak amplitude of 1.536 V is quantized into 128 levels using a mid-rise uniform quantizer. The quantization-noise power is –