Q1:

The correct sequence of subsystems in an FM receiver is

Q2:

Which of the following analog modulation scheme requires the minimum transmitted power and minimum channel band width?

Q3:

In phase modulation, the frequency deviation is

Q4:

An amplitude modulated signal is given by $X_{AM}(t)=A_c(1+\mu \cos {\omega }_{m}t)\cos {\omega }_{c}t$.

The frequency spectrum of AM signal is given by?

 

Q5:

The Disadvantage of FM over AM is

Q6:

The modulation index is, if f_m = 500 Hz, $\Delta$f = 2.25 kHz

Q7:

In pulse Code Modulation System

Q8:

The minimum step size required for a Delta modulator operating at 36 samples/sec to track the signal (here u(t) is the unit step function) x(t) = 125t (u(t) – u(t – 1)) + (250 – 125t) (u(t – 1) – u(t – 2)) So that slope overload is avoided, would be

Q9:

Quantizing error occurs in

Q10:

FSK is a system involving

Q11:

The PSD of a signal x(t) is given as 8$\pi$δ(w). then x(t) is given by

Q12:

Which of the following function is a valid PDF?

Q13:

A 10k symbols/sec source transmits four symbols with probabilities $P(X_1)=0.4,P(X_2)=0.3,P(X_3)=0.2,P(X_4)=\mathrm{0.1.}$

The information rate (in bits/sec) is when symbol rate(in symbol/sec) is 10 $\times {10}^3/\sec$

Q14:

Major advantage of FM over PM.

Q15:

A pre-emphasis circuit provides extra noise immunity by

Q16:

Autocorrelation is a function which matches –

Q17:

Power spectral density function is a ?

Q18:

The PDF of a random variable x is given by$f_x\left(x\right)=\{\begin{array}{cc}k,& a\le x\le b\\ 0,& other\text{ wise}\end{array}$                                                             where k is a constant if a =-1 and b=2, then p(|x|$\le$c) for c=1/2 is

Q19:

Bit 1 and 0 are transmitted with equal probability. At the receiver the PDF of the respective received signals for both bits are shown as below:

If the detection threshold is 1, the BER will be

Q20:

Which of the following statements about the matched filter in a communication receiver are correct?

1. it impulse response depends on the signal shape.

2. it maximizes the SNR at the detection instant.

3. it produces ISI.

4. it may produce phase error if synchronization is improper.

Select the correct answer from the codes given below.