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11
Man made noise are ___________ variations.
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Answer & Solution
Answer: Option A
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12
In TV transmission, picture signal is ___________ modulated
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Answer: Option C
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13
In TV transmission, sound signal is ___________ modulated
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Answer: Option B
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14
Most of the amplification in a superhetrodyne receiver occurs at ___________ stage
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Answer: Option A
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15
The superhetrodyne principle provides selectivity at ___________ stage
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Answer: Option B
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16
A high Q tuned circuit will permit an amplifier to have high ___________
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Answer: Option D
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17
If a radio receiver amplifies all the signal frequencies equally well, it is said to have high ___________
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Answer: Option D
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18
In amplitude modulation, bandwidth is ___________ the audio signal frequency
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Answer: Option C
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19
A 100 V carrier is made to vary between 160 V and 40 V by the signal. What is the modulation factor?
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Answer & Solution
Answer: Option D
Solution:
Understanding Modulation:
Imagine a radio station broadcasting. The carrier is like the main, constant radio wave. The signal is the information (music, voice) being sent.
Modulation changes the carrier wave based on the signal. Think of it like changing the volume (amplitude modulation) of the carrier wave according to the signal's strength.

In this question:
The carrier's voltage is 100V (this is the constant part).
The signal makes the carrier voltage vary between 160V (highest) and 40V (lowest).

Calculating Modulation Factor (m):
The modulation factor shows how much the carrier's amplitude changes due to the signal. It's calculated as follows:
m = (Vmax - Vmin) / (2 * Vc)
Where:
* Vmax = Maximum voltage of the modulated carrier (160V)
* Vmin = Minimum voltage of the modulated carrier (40V)
* Vc = Voltage of the unmodulated carrier (100V)

Let's calculate:
m = (160V - 40V) / (2 * 100V) = 120V / 200V = 0.6
The modulation factor (m) is 0.6. However this value is not present in option.
Another approach to calculate modulation factor:
m = (Vmax -Vc)/Vc
m = (160-100)/100 = 0.6
or
m = (Vc-Vmin)/Vc
m = (100-40)/100 = 0.6
Since 0.6 is not an option, the correct answer is D: None of the above.
20
In amplitude modulation, the ___________ of carrier is varied according to the strength of the signal.
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Answer & Solution
Answer: Option A
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