Question

The carrier freqeuncy of a station is 40 MHz. A resistor of 10k `Omega` and capacitor of CpF are available in the detector circuit. The possible value of C will be
A. 12
B. 8.2
C. 5.6
D. All of these

Answer 1

Correct Answer - D
Here, `R=10kOmega=10xx10^(3)Omega`
`C=12pF=12xx10^(-12)F`
`v_(c)=40MHz=40xx10^(6)Hz=4xx10^(7)Hz`.
Time period of carrier frequency
`T_(c)=(1)/(v_(c))-(1)/(4xx10^(7))=2.5xx10^(8)s`
time constant of C-R circuit,
As `T_(c)lt tau`, therefore, circuit is good enough for detection All the values of C given in the options are possible.