Q1:

Input to mid rise quantize is a Sinusoidal signal and the amplitude varies from – 3.5 to +3.5v Each sample is encoded in to 3 bits. The quantization power is.

Q2:

A stationary process X(t) is applied to a linear time invariant filter of impulse response h(t) producing an output of Y(t) assuming that X(t) is a white noise process with zero mean and power spectral density$\frac{No}{2}$then which of the following is obeyed?

Q3:

The spectral density and Autocorrelation function of white noise is

Q4:

Which one of the following is the correct statement?

If the value of a resistor creating thermal noise is doubled, the noise generated is.

Q5:

Input to mid rise quantize is a Sinusoidal signal and the amplitude varies from – 3.5 to +3.5v Each sample is encoded in to 3 bits. The quantization  noise power is.

Q6:

A symmetric three-level midrise quantizer is to be designed assuming equiprobable occurrence of all quantization levels.

The quantization noise power for the quantization between – a and +a in the figure is

Q7:

Let X(t) be a white Gaussian noise with $S_X(f)=\frac{N_0}{2}$. Assume that X(t) is input to an LTI system with h(t)=$e^{-t}u(t)$.

Let Y(t) be the output.

Find $R_Y(\tau )$?

Q8:

In a super heterodyne receiver the receiver is tuned to 1 MHz and the IF = 400 KHz. The local oscillator frequency is less than the tuned frequency then the local oscillator and image frequencies are.

Q9:

One of the main function of the RF amplifiers in a super – heterodyne receiver is to

Q10:

In the following scheme, if the spectrum M(f) of m(t) is as shown then the spectrum Y(f) of y(t) will be.

Q11:

The list-I (lists the attributes) and the list-II(lists of the modulation systems). Match the attribute to the modulation system that best meets it.

List – I	List – II
A Power efficient transmission of signals.	1 Conventional AM.
B Most bandwidth efficient transmission of voice signals.	2 FM
C Simplest receiver structure	3 VSB
D Bandwidth efficient transmission of signals with significant dc component	4 SSB-SC

 

Q12:

Resonant circuits are used in

Q13:

If output power of a radio receiver is doubled, its volume is increased by

Q14:

A superheterodyne receiver is to operate in the frequency range 550 kHz - 1650 kHz, with the intermediate frequency of 450 kHz. Let $R=\frac{C_{\min }}{C_{\max }}$ denote the required capacitance ratio of the local oscillator and I denote the image frequency (in kHz) of the incoming signal. If the receiver is tuned to 700 kHz, then

Q15:

The radio receivers mostly used now a days are