A Magic “ Tee is nothing but
1.Modification of E- Plane tee
2.Modification of H- Plane tee
3.Combination of E- plane & H- plane
4. Two E- plane tees connected in parallel
In Microwave communication links, The rain drop attenuation experienced is mainly due to
1.Absorption of microwave energy by water vapour
2.Resonance absorption of atomic vibration in water molecules
3.Scattering of microwaves by collection of water drops
4.Refraction of microwaves through liquid drop lenses formed by rain
The phenomenon of microwave signals following the curvature of earth is known as _______
1.Faraday effect
2.Ducting
3.Wave tilt
4.Troposcatter
Which of the following is the main advantage of microwave
1.Highly directive
2.Moves at the speed of light
3.Greater S/N ratio
4.High penetration power
Which of the following is used for amplification of microwave energy
1.Travelling wave tube
2.Magnetron
3.Reflex klystron
4.Gunn diode
A space between two cavities in two cavity klystron is _______
1.Drift space
2.Free space
3.Running space
4.Normal space
At Microwave frequencies , the size of the antenna becomes
1.Very large
2.Large
3.Small
4.Very Small
Due to the curvature of earth, microwave repeaters are placed at a distance of about
1.10 km
2. 50 km
3.150 km
4.250 km
For transverse electromagnetic wave propagation, we need a minimum of:
1.1 conductor
2.conductors
3.conductors
4.bunch of conductors
For which of the following reason, the Varactor diode is not useful at microwave frequencies
1.For electronic tuning
2.For frequency multiplication
3.As an Oscillator
4.As a parametric amplifier
HEMT(High Electron Mobility Transistor) used in microwave circuit is a _________
1.Source
2.Detector
3.High power amplifier
4.Low noise amplifier
In π mode operation of magnetron, the spokes due to phase focusing effect rotate at an angular velocity corresponding to ________
1.One pole / cycle
2.Two poles / cycle
3.Four poles / cycle
4.Six poles / cycle
In Microwave circuit , Wave guide section will act as a ______
1.Low pass filter
2.Band pass filter
3.High pass filter
4.Band reject filter
In Microwave power measurements using bolometer, the principle of working is the variation of
1.Inductance with absorption of power
2.Resistance with absorption of power
3.Capacitance with absorption of power
4.Cavity dimensions with heat generated by the power
In multicavity klystron additional cavities are inserted between buncher & catcher cavities to achieve
1.Higher Gain
2.Higher Efficiency
3.Higher Frequency
4.Higher Bandwidth
Magnetron is an _______
1.Amplifier
2.Oscillator
3.Phase shifter
4.Both phase shifter & amplifier
Microwave antenna aperture efficiency depends on _________
1.Feed pattern
2.Antenna aperture
3.Surface losses
4.low side lobe level
Most of the power measuring microwave devices measure
1.Average power
2.Peak power
3.Instantaneous power
4.None of these
On which of the following principle does Klystron operates
1.Amplitude Modulation
2.Frequency Modulation
3.Pulse Modulation
4.Velocity Modulation
PIN diode is suitable for use as a _____
1.Microwave switch
2.Microwave mixed diode
3.Microwave detector
4.None of these
Reflex klystron is a ______
1.Amplifier
2.Oscillato
3.Attenuator
4.Filter
Short term fading in microwave communication links can be overcome by
1.Increasing the transmitted power
2.Changing the antenna
3.Changing the modulation scheme
4.Diversity reception & transmission
The key difference between circuit theory and transmission line theory is:
1.circuit elements
2.voltage
3.current
4.electrical size
Transmission line is a _________ parameter network.
1.distributed
2.distributed
3.active
4.none of the mentioned
Traveling Wave Tube is __________
1.Oscillator
2.Tuned Amplifier
3.Wide Band Amplifier
4.Both Amplifier & Oscillator
Travelling wave parametric amplifiers are used to _______
1.Provide a greater gain
2.Reduce the number of Varactor diodes required
3.Avoid the need for cooling
4.Provide a greater bandwidth
Which of the following bands that comes under Microwave Band
1.C
2.D
3.E
4.all the above
Which of the following elements are taken in Microwave
1.Lumped Circuit Elements
2.Distributed Circuit Elements
3.Both a & b
4.None of these
Which of the following is one of the mode in Reflex Klystron
1.Give same frequency but different transit time
2.Are caused by spurious frequency modulation
3.Are just for theoretical consideration
4.Result from excessive transit time across resonator gap
Which of the following is the biggest advantage of the TRAPATT diode over IMPATT diod
1.Low Noise
2.High efficiency
3.Ability to operate at high frequencies
4.Lesser sensitivity to harmonics
Which of the following is the disadvantage of microstrips with respect to stripline circuit
1.Do not let themselves to be printed circuits
2.Are more likely to radiate
3.Are bulkier
4.Are more expensive & complex to manufacture
Which of the following is the major advantage of Travelling wave tube over Klystron
1.Higher gainy
2.Higher frequency
3.Higher Output
4.Higher bandwidth
Which of the following is the one of the reason why vacuum tubes eventually fail at microwave frequencies
1.Noise figure increases
2.Transit time becomes too short
3.Shunt capacitive reactances becomes too large
4.Series inductance reactances becomes too small
Which of the following is the semiconductor diode which can be used in switching circuits at microwave range
1.PIN diode
2.Tunnel diode
3.Varactor diode
4.Gunn diode
Which of the following microwave tube amplifier uses an axial magnetic field & radial electric field
1.Reflex Klystron
2.Coaxial Magnetron
3.Travelling Wave Magnetron
4.Crossed field amplifier
Which of the following noise becomes important at microwave frequencies
1.Shot noise
2.Flicker noise
3.Thermal noise
4.Transit time noise
_______ is the best medium for handling the large microwave power
1.Coaxial line
2.Rectangular wave guide
3.Strip line
4.Circular wave guide
_________ noise is produced in a microwave tube due to random nature of emission & electron flow
1.Partition noise
2.Shot noise
3.Johnson noise
4.Shannon noise
__________ is a region of Electromagnetic spectrum having frequency ranging from 1GHz to 100 GHz
1.Micro wave
2.UV
3.IRD
4.None of these