EC8491 CT IAT 1 PART B

What is the carrier frequency in an AM wave when its highest frequency component is 850Hz and the bandwidth of the signal is 50Hz? (CO1)(B5)

• 80 Hz

• 695 Hz

• 625 Hz

• 825 Hz

Calculate the power in one of the side band in SSBSC modulation when the carrier power is 124W and there is 80% modulation depth in the amplitude modulated signal. (CO1)(B5)

• 89.33 W

• 64.85 W

• 79.36 W

• 102 W

What is the effect on the transmitted power of AM signal when the modulation index changes from 0.8 to 1? (CO1)(B5)

• 0.1364

• 0.3856

• 1.088

• 0.5

Calculate the power in a DSB SC signal when the modulation is 60% with a carrier power of 600W. (CO1)(B5)

• 600 W

• 540 W

• 108 W

• 300 W

Calculate the modulation index when the un modulated carrier power is 15KW, and after modulation, carrier power is 17KW. (CO1)(B5)

• 68%

• 51.63%

• 82.58%

• 34.66%

Calculate the side band power in an SSBSC signal when there is 50% modulation and the carrier power is 50W. (CO1)(B5)

• 50 W

• 25 W

• 6.25 W

• 12.5 W

What is the change in the value of transmitted power when the modulation index changes from 0 to 1? (CO1)(B5)

• 100%

• 50%

• Same

• Unchanged

Calculate the power saved in an Amplitude Modulated wave when it is transmitted with 45% modulation

- Without carrier

- Without carrier and a sideband

(CO1)(B5)

• 90%, 95%

• 80%, 95%

• 90%, 85%

• 70%, 95%

If an AM signal is represented by

v = ( 15 + 3 Sin( 2Π * 5 * 10³ t) ) * Sin( 2Π * 0.5 * 10⁶ t) volts

i) Calculate the values of the frequencies of carrier and modulating signals. (CO1)(B5)

• 1.6 MHz and 8 KHz

• 2.6 MHz and 8 KHz

• 1.6 MHz and 6 KHz

• 2.6 MHz and 9 KHz

If an AM signal is represented by

v = ( 15 + 3 Sin( 2Π * 5 * 10³ t) ) * Sin( 2Π * 0.5 * 10⁶ t) volts

i)Calculate the value of modulation index. (CO1)(B5)

• 0.6

• 0.2

• 0.5

• 1