# Two dissimilar antennas having their maximum directivities equal

1.  Must have their beamwidhts also equal

2.  Cannot have their beamwidths equal because they are dissimilar antennas

3.  May not necessarily have their maximum power gains equal.

4.  Must have their effective aperture areas (capture areas) also equal

4

May not necessarily have their maximum power gains equal.

Explanation :
No Explanation available for this question

# The capacitance per unit length and the characteristic impedance of a lossless transmission line are C and Z0 respectively. The velocity of a travelling wave on the transmission line is

1.  Z0 C

2.

3.

4.

4

Explanation :
No Explanation available for this question

# A transverse electromagnetic wave with circular polarization is received by a dipole antenna. Due to polarization mismatch, the power transfer efficiency from the wave to the antenna is reduced to about

1.  50%

2.   33.3%

3.   25%

4.  0%

4

50\%

Explanation :
No Explanation available for this question

# A loss less transmission line having 50 Ω characteristic impedance and length λ/4 is short circuited at one end and connected to an ideal voltage source of 1V at the other end. The current drawn from the voltage source is

1.  0

2.  0.02

3.  ∞

4.  None of the above

4

0

Explanation :
No Explanation available for this question

# An electric dipole of moment P is placed in front of a grounded sphere as shown in the figure. The charge induced on the surface of the sphere is

1.  zero

2.  PR/d2

3.  PR2/d3

4.  PR2/d4

4

PR/d2

Explanation :
No Explanation available for this question

# A metal sphere with 1m radius and a surface charge density of 10 Coulombs/m2 is enclosed in a cube o 10m side. The total outward electric displacement normal to the surface of the cube is

1.  40 Coulombus

2.  10 Coulombus

3.  5 Coulombus

4.  None of the above

4

40 Coulombus

Explanation :
No Explanation available for this question

# The critical frequency of an ionosphere layer is 10MHz. What is the maximum launching angle from the horizon for which a 20MHz wave will be reflected by the layer

1.  00

2.  300

3.  450

4.  900

4

300

Explanation :
No Explanation available for this question

# The characteristic impedance Z0 of a lossless transmission line is equal to

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# Inside a hollow conducting sphere

1.  electric field is zero

2.  electric field is a non-zero constant

3.  electric field changes with the magnitude of the charge given to the conductor

4.  electric field changes with distance from the centre of the sphere

4

electric field is zero

Explanation :
No Explanation available for this question

1.  PQ

2.  PQ

3.  –n

4.  n

4