Microwave Communication

1. The velocity factor of a transmission line depends on

temperature skin effect relative permittivity of dielectric none of the above

2.A loss less line of characteristic impedance Z0 is terminated in pure reactance of -jZ0 value. VSWR is

10 2 1 infinity

3.In a klystron amplifier the input cavity is called

buncher catcher Pierce gun collector

4.In a circular waveguide the dominant mode is

TE01 TE11 TE20 TE21

5. The reflection coefficient on a line is 0.2 ∠45°. The SWR is

0.8 1.1 1.2 1.5

Radio Receivers

1.The noise generated by a resistor depends upon

its resistance value its operating temperature both its resistance value and operating temperature none of the above

2.In a superheterodyne receiver

the IF stage has better selectivity than RF stage the RF stage has better selectivity than IF stage the RF stage has same selectivity than IF stage none of the above

3.The function of an AM detector circuit is to

rectify the input signal discard the carrier provide audio signal all of the above

4.Which of the following should be used in order to prevent overloading or the last IF amplifier in a receiver?

Variable selectivity Variable sensitivity Double conversion Squelch

5.Most popular IF for receivers tuning to 540 to 1650 kHz is

433 kHz 455 kHz 545 kHz 555 kHz