Module -1 Introduction to Multiplexing

 The sampling technique having the minimum noise interference is

• Ideal sampling

• Natural sampling

• Flattop sampling

• All the abov

The instantaneous sampling

• Has a train of impulses

• Has the pulse width approaching zero value

• Has the negligible power content

• All of the above

The techniques used for sampling are

b.

• Instantaneous sampling

• Natural sampling

• Flat top sampling

• All of the above

A low pass filter is

• Passes the frequencies lower than the specified cut off frequency

• Rejects higher frequencies

• Is used to recover signal from sampled signal

• None of the above

Calculate the Nyquist rate for sampling when a continuous time signal is given byx(t) = 15 cos 300πt

• 300Hz

• 600Hz

• 150Hz

• 200Hz

Calculate the minimum sampling rate to avoid aliasing when a continuous time signal is given by x(t) = 5 cos 400πt

• 100 Hz

• 200 Hz

• 400 Hz

• 250 Hz

 A distorted signal of frequency f_m is recovered from a sampled signal if the sampling frequency f_s is

• f_s > 2f_m

• f_s < 2f_m

• f_s = 2f_m

• f_s ≥ 2f_m

In Unit impulse function

• Pulse width is zero

• Area of pulse curve is unity

• Height of pulse goes to infinity

• All of the above

 Unit step function is

• Exists only for positive side

• Is zero for negative side

• Discontinuous at time t=0

• All of the above

An even function f(x) for all values of x and x holds

• f(x) = f(-x)

• f(x) = -f(x)

• f(x) = f(x)f(-x)

• None of the above