Explanation: Signal to Noise ratio compares signal power to noise power. It determines how much signal is present in a transmitted wave compared to presence of noise. It is generally expressed in decibels(dB). For a hi-fi system, it should be equal to 50dB.

Explanation: In SSB-SC(Single Side Band Suppressed Carrier), the carrier is suppressed and either of the upper side-band and lower-sideband, are transmitted. This reduces it’s bandwidth to the frequency of the message signal.

Explanation: In television system in India, each of odd and even fields are scanned 25 times but alternately.

Explanation: Hilbert transform of a signal results in a signal with same amplitude but a phase shift of -90 degrees. Thus, a signal and it’s Hilbert transform have same amplitude spectrum i.e. they have same energy density spectrum and also correlation spectrum.

Power density of quadrature component is

Explanation: Frequency of DC signals is zero. For zero frequency, capacitive reactance XC is infinite as XC = 1/(f*C), where f is the frequency and C is the capacitance.

Explanation: A frequency tripler is a frequency multiplier in which an electronic circuit generates an output signal whose output frequency is a harmonic (multiple) of its input frequency. When a FM signal is passed through a frequency tripler, it increases its modulation index 3 times. So the modulation index of output is 3mf.

Explanation: Delta modulation is an analog-to-digital and digital-to-analog signal conversion technique used for transmission of voice information where quality is not of primary importance. It is the simplest form of differential pulse-code modulation (DPCM) where the difference between successive samples are encoded into n-bit data streams. The two major drawbacks in delta modulation are slope overload and granular noise. When step size becomes too small to track the original waveform it generates an error known as slope overload and granularity occurs when step size is too large.

Explanation: Angular separation between the two half-power (-3dB) points is known as beam width. It is usually expressed in degrees.