Which of the following is multiband HF receiving antenna?
Which of the following is multiband HF receiving antenna?
It is best to use for coupling a coaxial line to a parallel wire transmission line.
It is best to use for coupling a coaxial line to a parallel wire transmission line.
If a and b are the dimensions of waveguide then
If a and b are the dimensions of waveguide then
Which of the following statement regarding waveguides is incorrect?
Which of the following statement regarding waveguides is incorrect?
The virtual height of an ionospheric layer is __________ true height
The virtual height of an ionospheric layer is __________ true height
When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called
When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called
A waveguide operated below cut off frequency can be used as
A waveguide operated below cut off frequency can be used as
The frequency range for satellite communication is
The frequency range for satellite communication is
Tropospheric scatter propagation is not subject to any fading.
Tropospheric scatter propagation is not subject to any fading.
Which antenna is a wideband antenna?
Which antenna is a wideband antenna?
A loop antenna is a commonly used for
A loop antenna is a commonly used for
The skip distance is the maximum distance upto which ionospheric reflection is possible.
The skip distance is the maximum distance upto which ionospheric reflection is possible.
When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon
When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon
In H-plane metal plate lens the travelling wave front is
In H-plane metal plate lens the travelling wave front is
A square corner reflector is used in which of the following?
A square corner reflector is used in which of the following?
The potential that appears at a point in space due to the current which caused it is called potential
The potential that appears at a point in space due to the current which caused it is called potential
Parabolic and lens antenna used at
Parabolic and lens antenna used at
In microwave communication links, when fading due to rain attenuation occurs then technique adopted for solving the problem would include
In microwave communication links, when fading due to rain attenuation occurs then technique adopted for solving the problem would include
The useful magnetic flux obtainable from any closed surface is
The useful magnetic flux obtainable from any closed surface is
An open wire transmission line having a characteristic impedance of 600 ohms is terminated by a resistive load of 900 O. The standing wave ratio will be
An open wire transmission line having a characteristic impedance of 600 ohms is terminated by a resistive load of 900 O. The standing wave ratio will be
Which of the following impedance inversion is obtained?
Which of the following impedance inversion is obtained?
The radiation pattern of loop antenna is
The radiation pattern of loop antenna is
MUF is highest in periods of greatest sunspot activity.
MUF is highest in periods of greatest sunspot activity.
Tropospheric scatter is used with frequencies in the
Tropospheric scatter is used with frequencies in the
The radiation pattern of Hertzian dipole in the plane perpendicular to dipole is a
The radiation pattern of Hertzian dipole in the plane perpendicular to dipole is a
The power gain of a half-wave dipole with respect to an isotropic radiator is
The power gain of a half-wave dipole with respect to an isotropic radiator is
A rectangular waveguide is a
A rectangular waveguide is a
The radiation pattern of a parabola antenna is
The radiation pattern of a parabola antenna is
The divergence of a vector is a scalar, while the curl of a vector is another
The divergence of a vector is a scalar, while the curl of a vector is another
In case of antenna the ratio of the power radiated in the desired direction to the power radiated in the opposite direction is known as
In case of antenna the ratio of the power radiated in the desired direction to the power radiated in the opposite direction is known as
A Yagi antenna has a driven antenna
A Yagi antenna has a driven antenna
When a wave is incident from the more dense into a less dense medium at an angle equal to or exceeding the critical angle, the wave suffers total internal __________ .
When a wave is incident from the more dense into a less dense medium at an angle equal to or exceeding the critical angle, the wave suffers total internal __________ .
The wave in wave guide has
The wave in wave guide has
A satellite that simply reflect back the signals from one region of the earth to the other region is known as
A satellite that simply reflect back the signals from one region of the earth to the other region is known as
The critical frequency of ‘F’ layer is greater than 30 MHz.
The critical frequency of ‘F’ layer is greater than 30 MHz.
Which of the following will increase the antenna radiation efficiency?
Which of the following will increase the antenna radiation efficiency?
Radiation intensity in a given direction is the
Radiation intensity in a given direction is the
The attenuation in waveguide above to cut off frequency
The attenuation in waveguide above to cut off frequency
In a perfect conductor the incident and reflected wave combine to produce
In a perfect conductor the incident and reflected wave combine to produce
A square corner reflector is used in
A square corner reflector is used in
The main disadvantage of the two-hole directional coupler is
The main disadvantage of the two-hole directional coupler is
The transmitting antennas for lower frequencies (below 500 kHz) are generally
The transmitting antennas for lower frequencies (below 500 kHz) are generally
According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when
According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when
Due to which of the following reasons a lightning conductor on top of a building is made into a pointed spike?
Due to which of the following reasons a lightning conductor on top of a building is made into a pointed spike?
When a conductor moves in the field, so that it makes an angle 8 with the lines of flux, the force F is given as : F = Bl sin2 0.
When a conductor moves in the field, so that it makes an angle 8 with the lines of flux, the force F is given as : F = Bl sin2 0.
In case of surface waves the field strength at a point is directly proportional to
In case of surface waves the field strength at a point is directly proportional to
MUF is depend upon
MUF is depend upon
The minimum height of outer atmosphere is
The minimum height of outer atmosphere is
The static electric field in a conductor is
The static electric field in a conductor is
In an impedance smith chart, a clockwise movement along a constant resistance circle gives rise to
In an impedance smith chart, a clockwise movement along a constant resistance circle gives rise to
