MCQOPTIONS
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MCQOPTIONS
This section includes 72 Mcqs, each offering curated multiple-choice questions to sharpen your Active Filter Circuits knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A balanced modulator is used in standard AM to obtain the sum and difference frequencies. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2. |
The IF of an FM receiver operates at a center frequency of 455 kHz. |
| A. | True |
| B. | False |
| Answer» C. | |
| 3. |
The demodulator recovers the audio signal from the IF output. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4. |
A VCO is a variable capacitance oscillator. |
| A. | True |
| B. | False |
| Answer» C. | |
| 5. |
Frequency modulation is achieved by varying the frequency of an oscillator with a modulating signal. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
The mixer takes the RF signal along with the audio signal to produce the IF signal. |
| A. | True |
| B. | False |
| Answer» C. | |
| 7. |
Selectivity in a receiver is provided by the resonant circuits of the IF section. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8. |
An AM signal is made up of a carrier, an upper-side frequency, and a lower-side frequency. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 9. |
The purpose of the balanced modulator is to remove the carrier frequency. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 10. |
A certain fiber-optic cable has the following characteristics: n1 = 1.82 and n2 = 1.73. What is the value of θc? |
| A. | 71.90º |
| B. | 0.95º |
| C. | 18.1º |
| D. | 1.81º |
| Answer» B. 0.95º | |
| 11. |
Amplitude modulation is the process of varying the radio frequency with the modulating frequency. |
| A. | True |
| B. | False |
| Answer» C. | |
| 12. |
What does VCO stand for? |
| A. | Visually-Controlled Organization |
| B. | Voltage-Controlled Oscillator |
| C. | Voltage-Centered Oscilloscope |
| Answer» C. Voltage-Centered Oscilloscope | |
| 13. |
For a four-quadrant linear multiplier, what is the output voltage, given input voltages of Vx = +2 V and Vy = –10 V? |
| A. | +2 V |
| B. | +1 V |
| C. | –2 V |
| D. | –1 V |
| Answer» D. –1 V | |
| 14. |
On 14 December 1988, the first transatlantic telephone cable to use optical fiber was ______. |
| A. | TAT - 5 |
| B. | TAT - 7 |
| C. | TAT - 8 |
| D. | TAT - 6 |
| Answer» D. TAT - 6 | |
| 15. |
Frequencies in UHF range propagate by means of |
| A. | ground waves |
| B. | sky waves |
| C. | space waves |
| D. | surface waves |
| Answer» D. surface waves | |
| 16. |
Microwave resonators are used in1. Microwave oscillators2. Microwave narrowband amplifiers3. microwave frequency metersWhich of the above are correct? |
| A. | 1 and 2 only |
| B. | 1 and 3 only |
| C. | 2 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 17. |
A transponder is satellite equipment which |
| A. | Receives a signal from earth station and amplifies |
| B. | Changes the frequency of the received signal |
| C. | Retransmits the receive signal |
| D. | Does all of the above-mentioned functions |
| Answer» E. | |
| 18. |
A person using a Global Positioning System (GPS) can |
| A. | determine his location anywhere on the earth |
| B. | make weather forecast |
| C. | enhance the performance of his PC |
| D. | access Internet |
| Answer» B. make weather forecast | |
| 19. |
Calculate the output signal-to-noise ratio in dB for three identical links, given that the signal-to-noise ratio for any one link is 60 dB. |
| A. | 55.23 |
| B. | 27.61 |
| C. | 64.77 |
| D. | 32.38 |
| Answer» B. 27.61 | |
| 20. |
In a satellite communication, the uplink power level is generally high and power level of the received down link signal is low because:1. High signal attenuation due to free-space loss2. Limited available down link power3. Finite is dictated by the required coverage area |
| A. | 1 and 2 only |
| B. | 1 and 3 only |
| C. | 2 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 21. |
Full form of GAGAN (a satellite of ISRO) is - |
| A. | GIS Aided Geo Augmented Network |
| B. | GIS Aided Geo Augmented Navigation |
| C. | GPS Aided Geo Augmented Network |
| D. | GPS Aided Geo Augmented Navigation |
| Answer» E. | |
| 22. |
As per -WARC-1979 allocation, commercial communication satellites use bandwidth of |
| A. | 4 MHz |
| B. | 40 MHz |
| C. | 200 MHz |
| D. | 500 MHz |
| Answer» E. | |
| 23. |
For an earth station transmitter, with an antenna output power of 40 dBw (10,000 W), a back-off loss of 3 dB, a total branching and feeder loss of 3 dB, and transmit antenna gain of 4 dB, the effective isotropic radiated power (EIRP) will be |
| A. | 38 dBW |
| B. | 40 dBW |
| C. | 36 dBW |
| D. | 47 dBW |
| Answer» B. 40 dBW | |
| 24. |
Identify the disadvantage of satellite communication from the following |
| A. | No tracking is required in geostationary satellites |
| B. | Multiple access points are available in the satellite communication |
| C. | Due to ageing effect the deficiency of the satellites components decrease |
| D. | Low transmitting power and low receiving sensitivity are required by the satellite in close elliptical orbit |
| Answer» D. Low transmitting power and low receiving sensitivity are required by the satellite in close elliptical orbit | |
| 25. |
In satellite communication, Faraday rotation is caused by |
| A. | Plasma frequency |
| B. | Earth’s magnetic field |
| C. | Non-Gaussian nature of uplink noise when received in the downlink channel |
| D. | Ionospheric reflections that occur multiple times |
| Answer» C. Non-Gaussian nature of uplink noise when received in the downlink channel | |
| 26. |
Following are various layers in the atmosphere used for communications :(a) F2 Layer(b) D layer(c) F1 Layer(d) E LayerArrange these in terms of descending order of their height from earth.The correct sequence is: |
| A. | (a), (c), (d), (b) |
| B. | (b), (c), (d), (a) |
| C. | (a), (b), (d), (c) |
| D. | (c), (b), (a), (d) |
| Answer» B. (b), (c), (d), (a) | |
| 27. |
A satellite is orbiting in the equatorial plane with a period from perigee to the perigee of 12 h. If the eccentricity = 0.002, i = 0°, K1 = 66063.17 km2, μ = 3.99 x 1014 m3 / s2 and the earth's equatorial radius – 6378.14 km, the semi-major axis will be |
| A. | 34232 km |
| B. | 30424 km |
| C. | 26612 km |
| D. | 22804 km |
| Answer» D. 22804 km | |
| 28. |
An artificial satellite can be tracked very precisely from the earth by using? |
| A. | Zeeman effect |
| B. | Sonar |
| C. | Doppler effect |
| D. | Radar |
| Answer» D. Radar | |
| 29. |
List of few satellites manufactured by ISRO is given below along with the date of their launch. Which two of the following Satellites failed to reach the orbit ?SatelliteLaunch DateA. GSAT-28th May, 2003B. GSAT-415th April, 2010C. GSAT-5P25th December, 2010D. GSAT-1215th July, 2011 |
| A. | A and B |
| B. | B and C |
| C. | C and D |
| D. | D and A |
| Answer» C. C and D | |
| 30. |
A satellite communication link has both uplink and downlink C/N0 of 50dB-Hz. What would be overall link C/N0? |
| A. | 25dB-Hz |
| B. | 47dB-Hz |
| C. | 53dB-Hz |
| D. | 100dB-Hz |
| Answer» C. 53dB-Hz | |
| 31. |
In a communication system at 300 MHz, the receiving antenna gain is 8 dBi, the transmitting antenna gain is 10 dBi and the transmitting power level is 25 watts, the distance between the transmitter and the receiver is 1 km, the power received at the receiving antenna port (assuming the propagation medium is loss-less): |
| A. | 1 mW |
| B. | 9.97 μW |
| C. | 99.7 nW |
| D. | 0.0997 nW |
| Answer» C. 99.7 nW | |
| 32. |
Match the two lists and choose the correct answer from the code given below:List IList II(a) Travelling wave tube(i) kW – MW output power(b) Magnetron(ii) Low-frequency operation(c) Triodes(iii) Low power output(d) Gunn diode(iv) Slow wave circuits |
| A. | (a) – (iv), (b) – (ii), (c) – (i), (d) – (iii) |
| B. | (a) – (iv), (b) – (iii), (c) – (ii), (d) – (i) |
| C. | (a) – (iv), (b) – (i), (c) – (ii), (d) – (iii) |
| D. | (a) – (i), (b) – (iv), (c) – (iii), (d) – (ii) |
| Answer» D. (a) – (i), (b) – (iv), (c) – (iii), (d) – (ii) | |
| 33. |
GPS stands for ? |
| A. | Global Prime System |
| B. | Global Peace summit |
| C. | Global Postal System |
| D. | Global Positioning System |
| Answer» E. | |
| 34. |
Directions: The item consists of two statements, one labelled as the ‘Assertion (A)’ and the other as ‘Reason (R)’.You are to examine these two statements carefully and select the answers to the item using the codes given below:Assertion (A): In satellite communication technique, frequency reuse effectively doubles the bandwidth and information capacity of a satellite.Reason (R): Electromagnetic waves radiated from a transmitting antenna could be received by a distant receiving antenna by tuning the receiver in terms of frequency and polarization. |
| A. | Both A and R individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is not the correct explanation of A | |
| 35. |
Arrange the following in terms of theoretical attenuation in ascending order for a distance of 100 ft from the transmitter.(a) Ku-band(b) X-band(c) L-band(d) S-bandThe correct sequence of attenuation in ascending order is :Code : |
| A. | (c), (d), (b), (a) |
| B. | (a), (b), (c), (d) |
| C. | (a), (b), (d), (c) |
| D. | (d), (b), (c), (a) |
| Answer» B. (a), (b), (c), (d) | |
| 36. |
In a geostationary satellite communication system, a message signal is transmitted from an earth station via an uplink to a satellite, amplified in a transponder onboard the satellite, and then transmitted via a downlink to another earth station. The most popular frequency band for satellite communication is |
| A. | 16 MHz for the uplink and 14 MHz for the downlink |
| B. | 4 GHz for the uplink and 6 GHz for the downlink |
| C. | 6 GHz for the uplink and 4 GHz for the downlink |
| D. | 10 GHz for the downlink and 8 GHz for the uplink |
| Answer» D. 10 GHz for the downlink and 8 GHz for the uplink | |
| 37. |
An earth station at sea level communicates at an elevation angle of 35° with a GEO satellite. The vertical height of the stratiform rain is 3 km. The physical path length L through the rain will be nearly |
| A. | 6.3 km |
| B. | 5.2 km |
| C. | 4.1 km |
| D. | 3.0 km |
| Answer» C. 4.1 km | |
| 38. |
A low earth orbit satellite can provide large signal strength at an earth station because: |
| A. | Path loss is low |
| B. | These orbits are immune to noise |
| C. | Large solar power can be generated at these orbits |
| D. | Lower microwave frequencies in s-band can be used |
| Answer» B. These orbits are immune to noise | |
| 39. |
A satellite communication link has uplink C/No of 50 dB-Hz and downlink C/No of 47 dB-Hz. What would be overall link C/No? |
| A. | 44 dB-Hz |
| B. | 45 dB-Hz |
| C. | 48.5 dB-Hz |
| D. | 53 dB-Hz |
| Answer» C. 48.5 dB-Hz | |
| 40. |
A signal transmitted from an Earth station bounces back from a geostationary satellite, with an altitude of 35864 km from the Earth's surface. The range from the Earth station is 38200 km. The round trip time is about: (excluding processing delays and assuming c = 3 × 108 m/s) |
| A. | 255 ms |
| B. | 127 ms |
| C. | 239 ms |
| D. | 120 ms |
| Answer» B. 127 ms | |
| 41. |
Match the following lists in terms of Microwave bands:List – I(Bands)List – II(Frequency)(a) UHF(i) 300 - 3000 kHz(b) MF(ii) 26 - 40 GHz(c) Ka(iii) 4 - 8 GHz(d) C(iv) 300 - 3000 MHz |
| A. | (a) – (i), (b) – (ii), (c) – (iv), (d) – (iii) |
| B. | (a) – (iv), (b) – (ii), (c) – (i), (d) – (iii) |
| C. | (a) – (iii), (b) – (i), (c) – (ii), (d) – (iv) |
| D. | (a) – (iv), (b) – (i), (c) – (ii), (d) – (iii) |
| Answer» E. | |
| 42. |
In the ionosphere layer, the lowest frequency signal that penetrates the layer upon vertical incidence is given by |
| A. | fL = 81 NMax |
| B. | fL = 81 N2Max |
| C. | \(f_L=√(81 N_{Max} )\) |
| D. | \(f_L=81√(N_{Max} )\) |
| Answer» D. \(f_L=81√(N_{Max} )\) | |
| 43. |
Consider the following systems:(a) Satellite(b) Conventional Public Address System(c) Conventional Radio Receiver(d) Laser detectorArrange the above systems in order of their increasing order of operational frequency: |
| A. | (c), (b), (a), (d) |
| B. | (b), (c), (d), (a) |
| C. | (a), (b), (c), (d) |
| D. | (b), (c), (a), (d) |
| Answer» E. | |
| 44. |
For satellite communication the standard uplink and downlink frequencies, respectively, in C-band are: |
| A. | 6 GHz and 4 GHz |
| B. | 12 GHz and 8 GHz |
| C. | 4 GHz and 6 GHz |
| D. | 12 GHz and 9 GHz |
| Answer» B. 12 GHz and 8 GHz | |
| 45. |
Directions: The item consists of two statements, one labelled as the ‘Assertion (A)’ and the other as ‘Reason (R)’.You are to examine these two statements carefully and select the answers to the item using the codes given below:Assertion (A): It is not necessary to incorporate a very low noise amplifier in a communication satellite.Reason (R): The noise temperature of the satellite antenna is usually high, since the beam is covered by the earth. |
| A. | Both A and R individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» E. | |
| 46. |
India’s first satellite was named after _______. |
| A. | Varahamihira |
| B. | Ramanujam |
| C. | Bhaskara |
| D. | Aryabhatta |
| Answer» E. | |
| 47. |
IRS series satellite are used for - |
| A. | Forestry |
| B. | Education |
| C. | Remote sensing |
| D. | Astronomy |
| Answer» D. Astronomy | |
| 48. |
Match the following: Band nameFrequency range (GHz)a.Li. 3.9 – 8b,Cii. 1.0 – 1.5c.Kaiii. 18.0 – 26.5d.Kiv. 26.5 - 40 |
| A. | a – ii, b –i, c – iv, d - iii |
| B. | a – iii, b – ii, c – I, d - iv |
| C. | a – I, b – ii, c – iii, d - iv |
| D. | a – iv – b – iii, c – I, d - ii |
| Answer» B. a – iii, b – ii, c – I, d - iv | |
| 49. |
A satellite rotates about a planet at the rate of 360° per 24 hours. The planet attracts a 1 kg mass with 10 N force at a distance of 6000 km. The distance of the satellite from the centre of the planet is |
| A. | between 20,000 km and 30,000 km |
| B. | between 30,000 km and 40,000 km |
| C. | between 40,000 km and 50,000 km |
| D. | well above 50,000 km |
| Answer» D. well above 50,000 km | |
| 50. |
A communication link is to be set up between two stations 100 km apart using \(\frac{\lambda}{2}\)antennae to transmit 1 kW power. The operating frequency is 100 MHz and the directivity of the two antennae is 1.64. The maximum received power would be |
| A. | 3.06 × 10-8 W |
| B. | 1 × 10-9 W |
| C. | 1.53 × 10-8 W |
| D. | 6.12 × 10-9 W |
| Answer» D. 6.12 × 10-9 W | |