# Reflectors and lens antennas are commonly used

1.  In LF communication systems

2.  Not beyond 100KHz

3.   In the range 10MHz to 100MHz

4.  Above 100 MHz

4

Above 100 MHz

Explanation :
No Explanation available for this question

# Measurement of radiation resistance by reflection method is suitable for

1.  Parasitic element antennas

2.  Low frequency vertical conductor antenna

3.  All type of antennas

4.  None of the above

4

Parasitic element antennas

Explanation :
No Explanation available for this question

# The Thevenin equivalent of the network shown in Fig. I is 10 v in series with a resistance of 2 if now, a resistance of 3 ? is connected across AB as shown in Fig. II, the Thevenin equivalent of the modified network across AB will be

1.  10 V in series with 1.2 resistance

2.  6 V in series with 1.2 ? resistance

3.  10 V in series with 5 ? resistance

4.  6 V in series with 5 ? resistance

4

6 V in series with 1.2 ? resistance

Explanation :
No Explanation available for this question

# A certain network consist of two ideal voltage sources and a large number of ideal resistors. The power consumed in one of the resistor is 4 W when either of the two sources is active and the other is replaced by a short circuit. The power consumed by the same resistor when both the sources are simultaneously active would be

1.  Zero or 16 W

2.  4 W or 8 W

3.  Zero or 8 W

4.   8 W or 16 W

4

Zero or 8 W

Explanation :
No Explanation available for this question

# Antenna radiation efficiency is given by

1.

2.

3.

4.  None of these

4

Explanation :
No Explanation available for this question

# The circuit shown in the given figure is steady-state with switch ‘S’ open. The switch is closed at t=0. The values of vc(0+) and vc(∞) will be respectively

1.  2 V, 0 V

2.   0 V, 2 V

3.  2 V, 2 V

4.   0 V, 0 V

4

2 V, 0 V

Explanation :
No Explanation available for this question

# After closing the switch ‘S’ at t = 0, the current i(t) at any instant ‘t’ in the network shown in the given figure will be

1.  10 + 10 e100 t

2.  10 – 10 e100 t

3.  10 + 10 e-100t

4.  10 – 10 e-100t

4

10 – 10 e-100t

Explanation :
No Explanation available for this question

# Antenna aperture efficiency is given by

1.

2.

3.

4.  None of these

4

Explanation :
No Explanation available for this question

# The pole-zero configuration of a network transfer function is shown in the given figure. The magnitude of the transfer function will

1.  Decrease with frequency

2.  Increase with frequency

3.  Initially increase and then decrease with frequency

4.   Be independent of frequency

4

Be independent of frequency

Explanation :
No Explanation available for this question

# Consider the following statements 1. The two-port network shown below does NOT have an impedance matrix representation. 2. The following two-port does NOT have an admittance matrix representation. 3. A two-port network is said to be reciprocal if it satisfies z12 = z21 or an equivalent relationship. Of these statements

1.  1 and 2 are correct

2.   1, 2 and 3 are correct

3.  1 and 3 are correct

4.  None is correct

4