Avionics Mcqs - Set 5

1)   Which one of the following is not a true with respect to integrated modular avionics architecture?

a. Reduces weight
b. Easy maintenance
c. Hardware independent software
d. Increased life cycle
Answer  Explanation 

ANSWER: Increased life cycle

Explanation:
An integrated modular avionics architecture system reduces weight as the processors are centralized and relatively fewer components are required. It is also easy for maintenance as each component is a separate block which can be repaired or replaced easily. Modular avionics architecture ensures that the software used is hardware independent and can be updated in the future. However they do not ensure increased life cycle of the components, the life cycle of a component is same if the architecture is modular or any other type.


2)   The architecture where each component had its own sensors, processing and display is called as ________

a. Centralized architecture
b. Federated architecture
c. Disjoint or independent architecture
d. Open system architecture
Answer  Explanation 

ANSWER: Disjoint or independent architecture

Explanation:
Disjoint architecture is a First generation architecture where the avionics systems were stand alone black boxes which had separate sensors, processors and displays and were linked together by point to point wiring.


3)   Which one of the following is not true with respect with centralized architecture?

a. Complex design
b. Software can be written easily
c. Requires long data buses
d. Computers are in readily accessible bay
Answer  Explanation 

ANSWER: Complex design

Explanation:
The centralized architecture is one where all the components are linked to a single main frame computer for processing. The design is simple and software preparation and update is easy as the computer is easily accessible but requires long data buses running from the component to the computer which increases weight.


4)   Which type of avionic architecture was the first to use DIAS?

a. Centralized architecture
b. Pave pillar architecture
c. Federated architecture
d. Open system architecture
Answer  Explanation 

ANSWER: Federated architecture

Explanation:
Federated avionic architecture is a type of second generation architecture in which the data from each avionic component was converted into digital information and sent to the main frame computer. This technology was called the DIAS or Digital Avionics Information System.


5)   A time shared multiplex highway is used in Federated avionic architecture.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
The reason why time division multiplexing is possible is that the data transfer form the component to the computer is digital. This reduces a huge amount of wiring as the data transfer is serial and also the error is not propagated.


6)   What advantage does the concept of IS2 add to the pave pace avionic architecture?

a. Cost reduction
b. Better performance
c. Easy maintenance
d. Software compatibility
Answer  Explanation 

ANSWER: Cost reduction

Explanation:
The total cost of sensors used in avionic systems costs around 70% of the total avionic system. IS2 is the concept of an integrated sensor system in which the sensors are shared by different avionic components thus reducing the overall cost.


7)   Which avionic architecture allows the existence of heavily armed single seat fighters with a variety of weapons?

a. Federated architecture
b. Pave pillar architecture
c. Centralized architecture
d. Distributed architecture
Answer  Explanation 

ANSWER: Pave pillar architecture

Explanation:
In a typical single seat fighter aircraft the pilot has to play the role of both controlling the aircraft and weapons management as opposed to a twin seat aircraft where the pilot flies the plane and the RIO or Radar Intercept Officer manages the weapons. Pave pillar architecture allows the pilot to be the weapons system manager without which single seat fighter aircraft like F-22 and the F-35 would not have been possible.


8)   What type of avionic architecture is used in the JSF?

a. Pave pillar avionic architecture
b. Advanced integrated avionic architecture
c. Hierarchical avionic architecture
d. Centralized avionic architecture
Answer  Explanation 

ANSWER: Advanced integrated avionic architecture

Explanation:
The Joint Strike Fighter’s sensors, communications, and flight-control systems will blend together more tightly than any other combat aircraft in history, and will revolve around high-speed fiber-optic data buses and powerful commercial off-the-shelf microprocessors using advanced integrated avionic architecture.


9)   What is the cost-effective solution for UAV displays?

a. HMDs
b. HUDs
c. HDDs
d. No display for UAV
Answer  Explanation 

ANSWER: HMDs

Explanation:
Since the UAV is unmanned it does not require HDD or HUD but since the pilot is going to be on the ground controlling the UAV, HMDs are considered to be cost-effective and also show good performance and situational awareness.


10)   What is the failure probability for a UAV?

a. 10/hour
b. 10²/hour
c. 10-³/hour
d. 10-⁵/hour
Answer  Explanation 

ANSWER: 10-⁵/hour

Explanation:
Since the UAV is unmanned its failure would not be fatal, the failure probability for a UAV is less than that of a normal aircraft with a figure of 10-5/hour. Although, a failure might cause damage to the UAV and where it falls. The failure probability differs from mission to mission.


11)   Which one of the following is false with respect to TRN?

a. self contained
b. Unjammable
c. Low accuracy
d. No external systems needed
Answer  Explanation 

ANSWER: Low accuracy

Explanation:
No explanation is available for this question!


12)   A flight management system is not necessary for simple UAVs.

a. True
b. False
Answer  Explanation 

ANSWER: True

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.


13)   What is the altitude of HALE?

a. 20,000ft
b. 30,000ft
c. 40,000ft
d. 50,000ft
Answer  Explanation 

ANSWER: 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.


14)   What type of communication does the MQ-9 ‘reaper’ UCAV use?

a. Satellite
b. Radio
c. Infrared
d. Microwave
Answer  Explanation 

ANSWER: Satellite

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.


15)   In a radio controlled UAV, FHSS technology has more advantage than DSSS technology.

a. True
b. False
Answer  Explanation 

ANSWER: 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.


16)   Who discovered the radio waves?

a. Heinrich Hertz
b. Guglielmo Marconi
c. Thomas Edison
d. Alexander Bell
Answer  Explanation 

ANSWER: Heinrich Hertz

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.


17)   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
Answer  Explanation 

ANSWER: Transmitter

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.


18)   What type of communication is used for underwater communication?

a. Radio communication
b. Microwave communication
c. SONAR
d. Satellite communication
Answer  Explanation 

ANSWER: SONAR

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.


19)   Earth be considered as a communication medium.

a. True
b. False
Answer  Explanation 

ANSWER: True

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.


20)   A device that can both transmit and receive is called as?

a. Transducer
b. Duplexer
c. Radar
d. Transceivers
Answer  Explanation 

ANSWER: Duplexer

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.


21)   Radio transmission is always the speed of light irrespective of the medium.

a. True
b. False
Answer  Explanation 

ANSWER: False

Explanation:
Radio waves travel at the speed of light only in free space. Other all communication medium attenuates the signal and lowers the speed of signal propagation.


22)   What are the factors that affect signal propagation speed assuming no noise?

a. Wavelength of the signal
b. Frequency of the signal
c. Strength of electrical and magnetic fields
d. Permeability and permittivity of medium
Answer  Explanation 

ANSWER: Permeability and permittivity of medium

Explanation:
Since the EM waves are made of electric and magnetic fields, the resistance given by the medium to conduct electric and magnetic waves determine the speed of the EM wave. This is given by the permeability and the permittivity of the medium.


23)   Which of the following is not an example of simplex communication?

a. Radio broadcast
b. TV broadcast
c. UAV/drone control from ground
d. Walkie talkie
Answer  Explanation 

ANSWER: Walkie talkie

Explanation:
A simplex communication is when signal is sent from one end and is received at the other end. The communication in a walkie talkie is a two way communication.


24)   What type of communication is used in a commercial walkie talkie?

a. Simplex
b. Full duplex
c. Half duplex
d. Multiplex
Answer  Explanation 

ANSWER: Half duplex

Explanation:
Ia a walkie talkie the communication is two way but at a given time only one way communication is allowed. This type of communication is called as half duplex communication.


25)   What type of communication is used between ATC and aircraft?

a. Simplex
b. Full duplex
c. Half duplex
d. Half simplex
Answer  Explanation 

ANSWER: Half duplex

Explanation:
The communication between an aircraft and an ATC is half duplex meaning only one can speak at a time. The ATC asks or gives guidance for the aircraft, which the pilot has to fully hear before he can respond. If he responds before, the signal is not received by the ATC.


26)   In what type of communication is time division multiplexing possible?

a. Analog
b. Digital
c. Duplex
d. Simplex
Answer  Explanation 

ANSWER: Digital

Explanation:
In digital communication, the information can be quantized and transmitted. In time division multiplexing the information or digital data is quantized and transmitted in time slots which can be put together to get the original information.


27)   The process of making the signal more compatible with the medium is called as?

a. Modulation
b. Transmission
c. Encrypting
d. Multiplexing
Answer  Explanation 

ANSWER: Modulation

Explanation:
Modulation is the process of making the information signal more compatible with the medium. Modulation is the reason why we can have different channels on radio.


28)   The information signal is otherwise referred to as ___________

a. Digital signal
b. Analog signal
c. Baseband signal
d. Broadband signal
Answer  Explanation 

ANSWER: Baseband signal

Explanation:
The information signal, regardless of analog or digital type, is referred to as baseband signals. It could be voice, video or digital data and is modulated before transmission. In some case, baseband signals can be transmitted without modulation.


29)   Voice signals cannot be directly transmitted by radio.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
Baseband signals are, in many cases, incompatible with the medium. Theoretically, it is possible to transmit voice signals directly by radio, but due to the low frequency of these waves the antenna size required form transmission is too big.


30)   In frequency modulation, carrier frequency is always greater than baseband frequency.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
In frequency modulation, the baseband signal is overlapped or impressed in the carrier signal. The carrier can never have a lower frequency than the baseband signal as it would result in a huge data loss of the baseband signal.


31)   Which one of the following is not a type of modulation?

a. Frequency modulation
b. Amplitude Modulation
c. Pulse modulation
d. Phase amplitude modulation
Answer  Explanation 

ANSWER: Pulse modulation

Explanation:
Modulation is of three types, frequency modulation, amplitude modulation and phase modulation. Pulse modulation is a type of amplitude modulation.


32)   In amplitude modulation, which of the following varies?

a. Frequency of the carrier
b. Frequency of the information signal
c. Amplitude of the carrier wave
d. Amplitude of the information signal
Answer  Explanation 

ANSWER: Amplitude of the carrier wave

Explanation:
In amplitude modulation, the amplitude of the carrier wave is modulated with respect to the information signal. The frequency and the phase of both the carrier and the information signal remain constant.


33)   You have 5 information signals and only one transmitter. What technique will help in transmitting all the 5 signals?

a. Frequency modulation
b. Multiplexing
c. Amplification
d. Amplitude modulation
Answer  Explanation 

ANSWER: Multiplexing

Explanation:
Multiplexing is the process of transmitting more than one signal via a common transmitting medium. A device called a multiplexer is used for this purpose. The signal can be demultiplexed at the receiver end to retrieve the original information.


34)   What type of multiplexing is used in mobile phones?

a. Frequency division multiplexing
b. Time division multiplexing
c. Code division multiplexing
d. Phase multiplexing
Answer  Explanation 

ANSWER: Code division multiplexing

Explanation:
In code-division multiplexing, the signals to be transmitted are converted to digital data that is then uniquely coded with a faster binary code. The signals modulate a carrier on the same frequency. All use the same communications channel simultaneously. The unique coding is used at the receiver to select the desired signal.


35)   Which one of the following is not true with respect to amplitude modulation?

a. Less noise
b. Longer range
c. Lower bandwidth
d. Less complex circuits
Answer  Explanation 

ANSWER: Less noise

Explanation:
Although AM is much simpler and has a wider range due to atmospheric propagation, one of its major disadvantages is due to noise. Noise directly affects the amplitude of the signal and its hard to retrieve the original information.


36)   What type of multiplexing is used in serial buses?

a. Time division multiplexing
b. Code division multiplexing
c. Frequency division multiplexing
d. Phase multiplexing
Answer  Explanation 

ANSWER: Time division multiplexing

Explanation:
In serial buses, time division multiplexing is used to split the digital data, which is in binary numbers, into individual bits which occupy a particular time slot and is transmitted. The use of serial buses increases the limit on transmission speed and reduces noise.


37)   Cps is the unit of what?

a. Frequency
b. Amplitude
c. Phase
d. Gain
Answer  Explanation 

ANSWER: Frequency

Explanation:
Cps or cycles per second is an alternative unit for the frequency of an EM wave. The other unit for frequency is Hertz which is more commonly used around the world.


38)   The range of electromagnetic signals encompassing all frequencies is referred to as?

a. EM waves
b. EM frequency
c. EM spectrum
d. EM radiation
Answer  Explanation 

ANSWER: EM spectrum

Explanation:
The range of electromagnetic signals encompassing all frequencies is referred to as Electromagnetic spectrum. It includes radio waves, microwaves, optical waves, x-rays, gamma rays and cosmic waves.


39)   The distance that the wave travels in one cycle is called as?

a. Displacement
b. Wavelength
c. Cycle length
d. Cycle amplitude
Answer  Explanation 

ANSWER: Wavelength

Explanation:
The wavelength of a wave is the distance the wave travels in one cycle. The wavelength of a signal is represented by the Greek letter λ (lambda) and has the same units as length.


40)   What is the wavelength of a signal with a frequency of 150Mhz?

a. 10m
b. 2m
c. 5m
d. 20m
Answer  Explanation 

ANSWER: 2m

Explanation:
No explanation is available for this question!