# A point charge Q is located on the surface of a sphere of radius R as shown in the figure. The average electric field on the surface of the sphere

1.  infinite

2.

3.

4.  zero

4

Explanation :
No Explanation available for this question

# The intrinsic impedance of a lossy dielectric medium is given by

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# If a vertical dipole antenna is used in conjunction with a loop antenna for direction funding, then the field pattern obtained will be

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# A circular ring carrying a uniformly distributed charge Q and a point charges –Q on the axis of the ring are shown in the figure the magnitude of the dipole moment of the charge system is

1.  Qd

2.  Q R­2 /d

3.

4.  QR

4

Qd

Explanation :
No Explanation available for this question

# A 1 km long microwave link uses two antennas each having 30db gain.If the power transmitted by one antenna is 1w at 3 GHz the power received by the other antenna is approximately

1.  98.6 µw

2.   76.8 µw

3.  63.4 µw

4.  55.2 µw

4

63.4 µw

Explanation :
No Explanation available for this question

# An antenna , when radiating, has a highly direction radiation pattern. When the antenna is receiving, its radiation pattern

1.  is more directive

2.  is less directive

3.  is the same

4.  exhibits no directivity at all

4

is the same

Explanation :
No Explanation available for this question

# Two istropic antennas are separated by a distance of two wave length. If both the antennas are fed with currents of equal phase and magnitude, the number of lobes in radiation pattern in the horizontal plane are

1.  2

2.  4

3.  6

4.  8

4

4

Explanation :
No Explanation available for this question

# Copper behaves as a

1.  conductor always

2.  conductor or dielectric depending on the applied electric field strength

3.  conductor or dielectric depending on the frequency

4.  conductor or dielectric depending on the electric current density

4

conductor always

Explanation :
No Explanation available for this question

# Choose the correct statements for a wave proparating in an air filled rectangular wave guide:

1.  Guided wavelength is never less than the free space wave length.

2.  Wave impedance is never less than the free space impedance

3.   Phase velocities is never less than the free space velocity.

4.  TEM mode is possible if the dimeasions of the wave guide are properly chosen.

4

Phase velocities is never less than the free space velocity.

Explanation :
No Explanation available for this question

# A transmission line whose characteristic is a resistance

1.  Must be a lossless line

2.  Must be a distortionless line

3.  May not be a lossless line.

4.  May not be a distortionless line

4