Communication Engineering Objective Questions

1.  INTELSAT stands?

    a) International Telecommunications Satellite

    b) India Telecommunications Satellite

    c) Inter Telecommunications Satellite

    d) None of the above

 2. Kepler’s first law states?

    a) The path followed by a satellite around the primary will be an ellipse.

    b) The path followed by a satellite around the primary will be a circle.

    c) The path followed by a satellite around the primary will be a sphere

    d) None of the above

3. Kepler’s second law states?

  a) If t2-t1=t4-t3, then A12=A34.

  b) If t2+t1 = t4+t3, then A12=A34.

  c) If t2/t1=t4/t3, then A12=A34.

  d) All of above

 4. For an elliptical orbit?

    a) 0<e< 1

    b) 0= e

    c) 1= e

    d) None of the above

5. The orbital period in seconds?

    a) P =2π / n.

    b)  P=2 π / n2

    c) P= π / n

    d) None of the above

6. What is application of satellite systems?

   a) whether  forecasting

   b) Terrestrial communication

   c) point to point communication

   d) None of the above

7.  A random satellite moves in

   a) Random path

   b) Polar orbit

   c) Geostationary orbit

   d) Equatorial plane

8. Number of geo-stationary orbit is

    a) 0

    b) 1

    c) infinite

    d) Cannot be determined

9. Define Polar-orbiting Satellites.

  a) Polar orbiting Satellites orbit the earth in such a way as to cover the north & south   Polar Regions.

   b) Orbiting Satellites orbit the earth in such a way as to cover the east & west Polar Regions

   c) Either (a) & (b)

   d) None of the above

10. Atmospheric drag has negligible effect on

    a) Geostationary satellites

    b) MEO                      

    c) LEO

    d) None of these

11. In analog technique of modulation in satellite, the most commonly employed system is

     a) AM

    b) FM

    c) PAM

   d) PWM

12. The angle subtended by earth at a geostationary communication satellite is nearly

    a) 66.5

   b) 47.34

   c) 17.34

   d) 7.34

13. The main advantage of satellite communication is

    a) Low cost

    b) Low distortion

    c) High reliability

    d) High band width

14. Geostationary satellites are located at a height of

    a) 3600 km from earth’s surface

    b) 36000 km from earth’s surface

    c) 360,000 km from earth’s surface

    d) 3600,000 km from earth’s surface

15. The velocity of a geostationary satellite is nearly

     a) 1255 km/hr

     b) 6757 km/hr

     c) 9422 km/hr

     d) 12644 km/hr

16. A synchronous satellite orbits the earth once in

    a) 24 hours

    b) 12 hours

    c) 6 hours

    d) 1 hours

17. Calculate the radius of a circular orbit for which the period is 1 day?

    a) 42.241Km

    b) 42.241m

    c) 4.241Km

   d) 2.241Km

18. The order of optical frequencies is

    a) MHz

    b) GHz

    c) KHz

    d) TeraHz

19. Following is not a usual classification of optical fibre

     a) Single-mode step index

    b) Single mode graded index

    c) Multimode step index

    d) Multimode graded index

20. A  certain  optical  fiber  has  a  refractive  index  of  clad  (n1)  =1.40 and  that of core   

            (n₂)  =1.05.Its Numerical aperture will be

     a) 0.8575

     b) 0.9260

     c) 0.3500

     d) 0.1585

                                                   

21. Light travels in optical fiber by which mechanism

   a) Refraction

   b) Reflection

   c) Scattering

   d) Total Internal Reflection

22. Losses in optical fiber can be caused by which of the following

     1) Impurities

     2) Micro bending

     3) Stepped-Index operation                              

a) 1 & 3

b) 2&3

c) 1&2

d) 3 only

23. The optical fiber uses ……..portion of EM spectrum

    a) IR

    b) VHF

    c) UHF

    d) HF

24. A glass fiber has refractive indices n₁ of 1.5 and n2 of 1.Assuming c=3x10⁸ m/s, the       multipath time dispersion will be

  a) 2.5 ns/m

  b) 2.5µs/m

  c) 5ns/m

  d) 5 µs/m

25.  Dispersion in an optical fiber used in a communication link is of which type?

   a) Angular Dispersion

   b) Modal dispersion

   c) Chromatic dispersion

   d) Dispersion arising due to structural irregularities in the fiber

26. The numerical aperture (NA) and acceptance angle are related as

a) NA=sinӨ

b) NA=sin^-1Ө

c) NA= (1-sin²Ө)^1/2

d) None

27. A single mode fiber doesn’t suffer which type of dispersion?

    a) Waveguide dispersion

    b) Material Dispersion

    c) Intermodal Dispersion

   d) Polarization mode Dispersion

28. A certain optical fiber has a refractive index of clad (n₁) =1.40.its numerical apertures is   0.9260 then find refractive index of core (n₂)

  a) 1.50

  b) 1.05

  c) 1.005

  d) None