When high frequency is given,(here avove 1khz) ,it will pass through, but when the low frequency is given, the amplitude will start to reduce.
Change the frequency of the supply
Calculation:
I want the cut off frequency around 1khz, having 1kΩ resistor, while Input voltage=10v
C=1/(2π fR) = 1/(2π*1khz*1kΩ ) =159nf=160nf(approx)
Vout=Vin/√2=10/√2=7.07v
You can use op amp like me to amplify your voltage
