Q.1
It is possible to increase the maximum range of a radar equipment by
Q.2
A high-power microwave pulse of the order of megawatts can be generated by a
Q.3
In a pulsed radar set, the STC circuit is used to
Q.4
Which causes multipath or frequency selective fading?
Q.5
If k-factor is greater than 1, the array beam is bent
Q.6
___________ is a microwave device in which the frequency of operation is determined by the biasing field strength.
  • vtm
  • gyratron
  • helix bwo
  • none of the mentioned
Q.7
In a___________ oscillator, the RF wave travels along the helix from the collector towards the electron gun.
  • interaction oscillator
  • backward wave oscillator
  • magnetrons
  • none o the mentioned
Q.8
___________ is a single cavity klystron tube that operates as on oscillator by using a reflector electrode after the cavity.
  • backward wave oscillator
  • reflex klystron
  • travelling wave tube
  • magnetrons
Q.9
To prevent an IMPATT diode from burning, a constant bias source is used to maintain__________ at safe limit.
  • average current
  • average voltage
  • average bias voltage
  • average resistance
Q.10
A class B amplifier consists of___________ transistors in order to conduct the input signal over the entire cycle.
  • 1
  • 2
  • 4
  • 6
Q.11
______________amplifiers are linear circuits, where the transistor is biased to conduct over the entire range of the input signal cycle.
  • class a amplifiers
  • class b amplifiers
  • class c amplifiers
  • none of the mentioned
Q.12
In transistor oscillators, FET and BJT are used. Instability is achieved by:
  • giving a negative feedback
  • giving a positive feedback
  • using a tank circuit
  • none of the mentioned
Q.13
In transistor oscillators, the requirement of a negative resistance device is satisfied using a varactor diode.
  • true
  • false
Q.14
To achieve stable oscillation, Zin + ZL=0 is the only necessary and sufficient condition to be satisfied by the microwave oscillator.
  • true
  • false
Q.15
For achieving steady state oscillation, the condition to be satisfied in terms of reflection coefficients is:
  • Гin=Гl
  • Гin=-Гl
  • Гin=1/Гl
  • none of the mentioned
Q.16
In a microwave oscillator, a load of 50+is connected across a negative resistance device of impedance -50-50j. Steady state oscillation is not achieved in the oscillator.
  • true
  • false
Q.17
Any device with negative impedance as its characteristic property can be called:
  • energy source
  • energy sink
  • oscillator
  • none of the mentioned
Q.18
The equivalent circuit of a quartz crystal has LCR arm capacitance of 12nF and inductance of 3mH and parallel arm capacitance of 4nF. Parallel resonant frequency for the circuit is:
  • 3 mhz
  • 0.3 mhz
  • 6 mhz
  • 9 mhz
Q.19
Parallel resonant frequency of quartz crystal is given by:
  • 1/ √(lcₒc/(cₒ+c))
  • 1/√lc
  • 1/√lcₒ
  • 1/ √(l(cₒ+c) )
Q.20
In the equivalent circuit of a quartz crystal, LCR arm has an inductance of 4 mH and capacitor has a value of 4nF, then the series resonant frequency of the oscillator is:
  • 0.25 mhz
  • 2.5 mhz
  • 25 mhz
  • 5 mhz
0 h : 0 m : 1 s