1. Which one of the following is false with respect to TRN?
a) self contained
b) Unjammable
c) Low accuracy
d) No external systems needed
Explanation: Terrain reference navigation, TRN, systems are used in cruise missiles and aircraft. One of the major advantage in UAV/UCAV applications is that they are completely self-contained and unjammable as well as of high accuracy. They are completely independent of any external systems such as satellites or ground stations.
2. A flight management system is not necessary for simple UAVs.
a) True
b) False
Explanation: Although an FMS is needed for UAVs, for simple UAVs such as radio controlled models does not require FMS. The FMS functions of many smaller UAVs are carried in the ground station.
3. What is the altitude of HALE?
a) 20,000ft
b) 30,000ft
c) 40,000ft
d) 50,000ft
Explanation: HALE corresponds to High Altitude and Long Endurance aircraft. It has a service ceiling of 50,000ft and an endurance greater than 20hrs
4. What type of communication does the MQ-9 ‘reaper’ UCAV use?
a) Satellite
b) Radio
c) Infrared
d) Microwave
Explanation: Since the MQ-9 has an endurance of 28hrs and range of 3,200nm it needs a communication system that is not affected by the curvature of the Earth. Satellite communication system is best suited for this as a minimum of 3 satellites is enough to have communication around the world using the technique of triangulation
5. In a radio controlled UAV, FHSS technology has more advantage than DSSS technology.
a) True
b) False
Explanation: FHSS stands for frequency hopping spread spectrum and DSSS for Direct sequence spread spectrum. DSSS technology is more advantageous as it is less susceptible to noise and can not be easily jammed or hijacked.
6. Who discovered the radio waves?
a) Heinrich Hertz
b) Guglielmo Marconi
c) Thomas Edison
d) Alexander Bell
Explanation: The German physicist, Heinrich Hertz, first applied the theory given by Maxwell to prove the existence of radio waves in 1887. To honor him the unit of frequency is given his name.
7. What is the component that converts an electrical signal into a signal suitable for transmission in a given medium called?
a) Transmitter
b) Receiver
c) Amplifier
d) Duplexer
Explanation: A transmitter is an electronic component that converts the electric signals into a signal that is suitable for transmission in any given medium. It could be wires, air, water, land or even space
8. What type of communication is used for underwater communication?
a) Radio communication
b) Microwave communication
c) SONAR
d) Satellite communication
Explanation: SONAR or SOund Navigation and Ranging is the transmission of information using sound waves. Since seawater is saline, it shorts out the electrical field in the radio waves and hence radio communication cannot be used.
9. Earth be considered as a communication medium.
a) True
b) False
Explanation: Earth can be considered as a communication medium as it can carry low frequency sound waves as well as conduct electricity. Communication for some submarines uses earth as a communication medium.
10. A device that can both transmit and receive is called as?
a) Transducer
b) Duplexer
c) Radar
d) Transceivers
Explanation: A transceiver is a device that contains the necessary electronic components for both transmission and receiving in the same medium. They have a common power supply and a common antenna for transmitting and receiving.