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Given below are two statement : Statement-I : A speech signal of 2 kHz is used to modulate a carrier signal of 1 MHz. The band width required for the signal is 4 kHz. Statement-II : The side band frequencies are 1002 kHz and 998 kHz. In the light of above statements, choose the correct answer from the options given below :

1. Statement I is true but Statement II is false
2. Statement I is false but Statement II is true
3. Both Statement I and Statement II are true
4. Both Statement I and Statement II are false

Correct answer: Statement I is false but Statement II is true

Solution

Statement I is incorrect because the bandwidth required for amplitude modulation is actually twice the frequency of the modulating signal, which would be 4 kHz, but the total bandwidth should be considered in relation to the carrier frequency. Statement II is correct as the sideband frequencies are indeed calculated by adding and subtracting the modulating frequency from the carrier frequency, resulting in 1002 kHz and 998 kHz.

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