Which of the following operating frequencies is used for the modern loran navigational system? Loran B: 900 kHz Loran D: 10.2 kHz Loran C: 100 kHz Loran A: 1950 kHz TRUE ANSWER : ? YOUR ANSWER : ?
A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be No noticeable effect A decrease in range A decrease in gain A reduction in horizontal resolution TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is used as an oscillator device in the SHF band? Tunnel diode Both B and C Thyratron tube Klystron tube TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is used as a high power microwave oscillator? Thyratron Klystron Reflex-klystron Magnetron TRUE ANSWER : ? YOUR ANSWER : ?
At what position is the input signal inserted into a traveling-wave tube? At the collector At the collector end of the helix At the cathode end of the helix At the control grid of the electron gun TRUE ANSWER : ? YOUR ANSWER : ?
The antenna separations (in meters) required for optimum operation of a space diversity system can be calculated from:where R = effective earth radius (m) and L = path length (m) S = λR/RL S = 2λR/L S = 3λR/L S = λR/L TRUE ANSWER : ? YOUR ANSWER : ?
In a pulsed radar set, the function of the duplexer is to Allow the transmitter and the receiver to operate from a common antenna Prevent frequency drift in the klystron All of these Aid in calibrating the display unit TRUE ANSWER : ? YOUR ANSWER : ?
__________ is the progressive decrease of signal strength with increasing distance. Modulation Propagation Attenuation Radiation TRUE ANSWER : ? YOUR ANSWER : ?
The cavity resonator Has a low Q factor for narrow operation. Is equivalent to an LC resonant circuit Produces a frequency which is independent of the cavity size. In a reflect klystron has its output taken from the reflector plate TRUE ANSWER : ? YOUR ANSWER : ?
The frequency of the oscillation generated by a magnetron, is mainly determined by The dimension of each cavity resonator The ratio of the dc cathode voltage to the magnetic flux density The flux density of the external magnet The number of the cavity resonators TRUE ANSWER : ? YOUR ANSWER : ?