# The fourier transform F{e-1 u(t)} is equal to 1/1+j2πf therefore ,F{1/1+j2πt} is

1.  e f u(f)

2.  e –f u(f)

3.  e f u(-f)

4.  e –f u(f)

4

e –f u(f)

Explanation :
No Explanation available for this question

# A linear phase channel with phase delay TP and group delay Tg must have

1.  TP= Tg=constant

2.  TP ∝f and Tg∝f

3.  TP = constant and Tg∝f

4.  TP ∝f and Tg =constant

4

TP = constant and Tg∝f

Explanation :
No Explanation available for this question

# A 1 MHz sinusoidal carrier is amplitude modulated by a symmetrical square wave of period 100µsec. Which of the following frequencies will NOT be present in the modulated signal

1.  990 KHz

2.  1010 KHz

3.  1020 KHz

4.  1030 KHz

4

1030 KHz

Explanation :
No Explanation available for this question

# For a bit-rate of 8 Kbps, the best possible values of the transmitted  frequencies in a coherent binary FSK system are

1.  16 KHz and 20 KHz

2.  20 KHz and 32 KHz

3.  20 KHz and 40 KHz

4.  32 KHz and 40 KHz

4

20 KHz and 32 KHz

Explanation :
No Explanation available for this question

# The  line-of-sight  communication  requires  the  transmit  and  receive  antenna  to face each other. If the transmit antenna is vertically polarized, for best reception the receive antenna should be

1.  horizontally polarized

2.  vertically polarized

3.  at 45° with respect to horizontal polarization

4.  at 45° with respect to vertical polarization

4

horizontally polarized

Explanation :
No Explanation available for this question

# Consider  a  sampled  signal   where X(t)=10cos(8π× 10 3)t And T s=100µsec when When  y(t)  is  passed  through  an  ideal  low-pass filter with a cutoff frequency of 5KHz, the output of the filter is

1.  5 ×10 -6cos (8 π×10 3) t

2.  5 ×10 -5cos (8 π×10 3) t

3.  5 ×10 -1cos (8 π×10 3) t

4.  10 cos (8 π×10 3) t

4

5 ×10 -6cos (8 π×10 3) t

Explanation :
No Explanation available for this question

# The VSWR can have any value between

1.  0 and 1

2.  -1 and +1

3.  0 and ∞

4.  1 and ∞

4

1 and ∞

Explanation :
No Explanation available for this question

# In an impedance Smith chart, a clockwise movement along a constant resistance circle gives rise to

1.  a decrease in the value of reactance

2.  an increase in the value of reactance

3.  no change in the reactance value

4.  no change in the impedance value

4

an increase in the value of reactance

Explanation :
No Explanation available for this question

# The phase velocity for the TE10-mode  in an air-filled rectangular waveguide  is (c is the velocity of plane waves in free space)

1.  less than c

2.  equal to c

3.  greater than c

4.  none of the above

4

equal to c

Explanation :
No Explanation available for this question

1.  16

2.  40/3?

3.  60?

4.  20?

4