A noiseless $4-$kHz channel is sampled every $1$ msec. what is the maximum data rate?

How does the maximum data rate change if the channel is noisy, with a signal$-$to$-$noise ratio of

$20$dB$?($please analyze based on Nyquist theorem and Shannon theorem. Note that, the S$/$N in

Shannon equation is just a ratio, NOT in the unit of $$dB$)$A noiseless $4-$kHz channel is sampled every $1$ msec. what is the maximum data rate?

How does the maximum data rate change if the channel is noisy, with a signal$-$to$-$noise ratio of

$20$dB$?($please analyze based on Nyquist theorem and Shannon theorem. Note that, the S$/$N in

Shannon equation is just a ratio, NOT in the unit of $$dB$)$