| 1. | A super heterodyne radio receiver with an IF of 455 KHz is tuned to a signal at 1205KHz, the image frequency is ? | |
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910 KHz
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1660 KHz
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2865 KHz
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None of these
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Report Question| 2. | An antenna has 40 as antenna resistance and 60 as radiation resistance. What is the efficiency of the antenna ? | |
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3%
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70%
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60%
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80%
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| 3. | When the antenna diameter is doubled, the gain of the antenna ? | |
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Reduces by half
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Increases by 3 dB
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Reduces by 3 dB
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Increases by 6 dB
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| 4. | The MODEM is used with a personal computer to do which of the following ? | |
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Convert from serial to parallel and vice versa
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Convert signals between TTL and RS232 C standard and vice versa
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Convert from digital to analog signals an vice versa
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To convert the computer to a long distance communication link
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| 5. | Which one of the following types of noise gains importance at high frequency ? | |
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Shot noise
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Random noise
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Impulse noise
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Transit-time noise
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| 6. | Intrinsic impedance of free space is given as ? | |
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75
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73
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377
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300
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| 7. | A coaxial transmission line carrying an RF signal is perfectly method to the load. Consider the cross-section of the line, at a plane where the instantaneous voltage is at its maximum value. How will the curl of the E-field very over this cross-section ? | |
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Increases from the center to the outer conductor
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Decreases from the center to the outer conductor
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Zero everywhere
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Constant value proportional to the RF voltage
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| 8. | Equalizing in TV are sent during ? | |
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Horizontal blanking
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Vertical blanking
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Serrations slots
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The horizontal retrace
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| 9. | The electric field measured in the far field of an antenna at a distance of 50m is 1V/m. the average power density at a distance of 500 mC from the antenna is ? | |
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26.6
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0.1
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10
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13.3
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| 10. | Ratio of skin depths of an Electromagnetic wave inside the conductor for the corresponding frequencies at GHz and 9 GHz, considering the same material properties for both the frequencies is ? | |
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9 : 4
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4 : 9
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3 : 2
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2 : 3
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