Mobile Communication 5

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Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Mobile Communication 5

Part 5: List for questions and answers of Mobile Communication

 

Q1. Umbrella cell approach

a) Uses large and small cells

b) Uses different antenna heights

c) Is used for high speed users with large coverage area and low speed users with small coverage area

d) all of the above

 

Q2. Interference in cellular systems is caused by

a) Two base stations operating in same frequency band

b) Two calls in progress in nearby mobile stations

c) Leakage of energy signals by non cellular systems into cellular frequency band

d) all of the above

 

Q3. Interference in frequency bands may lead to

a) Cross talk

b) Missed calls

c) Blocked calls

d) all of the above

 

Q4. Co- channel reuse ratio depends upon

a) Radius of the cell

b) Distance between the centers of the co channel cells

c) Frequency allocation of nearest cells

d) both a) and b)

 

Q5. Increase in co- channel reuse ratio indicates

a) Better transmission quality

b) Larger capacity

c) Low co-channel interference

d) both a) and c)

 

Q6. Grade of service refers to

a) Accommodating large number of users in limited spectrum

b) ability of a user to access trunked system during busy hour

c) Two calls in progress in nearby mobile stations

d) High speed users with large coverage area 

 

Q7. Traffic intensity is expressed in

a) Erlangs /mhz /km2

b) erlangs

c) I/ sec

d) Db/sec

 

Q8. The techniques used to improve the capacity of cellular systems are

a) Splitting

b) Sectoring

c) Coverage zone approach

d) all of the above

 

Q9. Distributed antenna systems are used at

a) Transmitters of mobile systems

b) Transmitters of base stations

c) inputs and outputs of repeaters

d) Receivers of mobile stations

 

Q10. Antenna down tilting refers to

a) focusing radio energy towards ground

b) Decreasing the strength of antenna

c) Decreasing the s/n ratio at the antenna input

d) All of the above

 

Q11. The rainbow pattern seen on a cd is an example of

a) Reflection

b) Refraction

c) diffraction

d) None of the above

 

Q12. When a wave falls on a perfect conductor

a) Wave is partially reflected and partially transmitted

b) all incident energy is reflected back without loss of energy

c) Part of energy gets absorbed

d) Both (a) and (c)

 

Q13. Brewster angle is the angle at which

a) No reflection occurs at the first medium

b) Reflection coefficient is zero

c) The wave gets refracted in the direction of source

d) both a) and b) 

 

Q14. Coherence time refers to

a) Time required to attain a call with the busy base station

b) Time required for synchronization between the transmitter and the receiver

c) minimum time for change in magnitude and phase of the channel

d) None of the above

 

Q15. Fading due to shadowing is

a) Fading due to large obstructions

b) Large coherence time of the channel as compared to the delay constraints

c) Small coherence time of the channel as compared to the delay constraints

d) both a) and b)

 

Q16. Doppler spread refers to

a) signal fading due to doppler shift in the channel

b) Temporary failure of message transfer

c) Large coherence time of the channel as compared to the delay constraints

d) All of the above

 

Q17. Impulse response of a multipath channel is determined by the fact that

a) Mobile radio channel may be modeled as linear filter

b) Impulse response is time varying

c) both a) and b)

d) None of the above

 

Q18. The received signal from a multipath channel is expressed as

a) convolution of transmitted signal and impulse response

b) Addition of transmitted signal and impulse response

c) Subtraction of transmitted signal and impulse response

d) None of the above

 

Q19. Direct rf pulse system helps in calculating

a) Impulse response in frequency domain

b) Impulse response in phase domain

c) Power delay of the channel

d) all of the above

 

Q20. The power delay profile helps in determining

a) Excess delay

b) Rms delay spread

c) Excess delay spread

d) all of the above 

 

Part 5: List for questions and answers of Mobile Communication

 

Q1. Answer: d

 

Q2. Answer: d

 

Q3. Answer: d

 

Q4. Answer: d

 

Q5. Answer: d

 

Q6. Answer: b

 

Q7. Answer: b

 

Q8. Answer: d

 

Q9. Answer: c

 

Q10. Answer: a

 

Q11. Answer: c

 

Q12. Answer: b

 

Q13. Answer: d

 

Q14. Answer: c

 

Q15. Answer: d

 

Q16. Answer: a

 

Q17. Answer: c

 

Q18. Answer: a

 

Q19. Answer: d

 

Q20. Answer: d