A) 2900 kHz
B) 2750 kHz
C) 2250 kHz
D) 2000 kz
Correct Answer: D
Solution :
Amplitude modulated wave consist of three Waves \[{{f}_{c}},\text{ }{{f}_{c}}-\text{ }{{f}_{m}}-{{f}_{c}}+{{f}_{m}}\] \[{{f}_{c}}-{{f}_{m}}\text{ }and\text{ }{{f}_{c}}+{{f}_{m}}\] are side band frequency \[{{f}_{c}}=250\times 10\] = 250 kHz Left Side Band \[=LSB={{f}_{c}}-{{f}_{m}}=2500250=~2250\text{ }kHz\] Right Side Band \[=RSB={{f}_{c}}+{{f}_{m}}\] \[=\text{ }2500+250\] \[=2750\text{ }kHz\] One new signal is of 250 Hz For this carrier wave should be taken in such a way that. LSB, RSB, fc do not overlap with previous frequencies. \[\therefore \,\,\text{ }{{f}_{c}}=2000\] as \[LSB=1750\text{ }kHz\] \[RSB=2250\text{ }kHz\] NTA has given answer but answer should be .You need to login to perform this action.
You will be redirected in
3 sec