State two advantages of the transmission of data in digital form rather than in analogue form.
An analogue signal 
is converted into a digital signal D using an analogue-to-digital converter (ADC). After transmission of the digital signal, it is converted back to an analogue signal 
using a digital-to-analogue converter (DAC), as illustrated in the figure below.
Outline the process by which the ADC converts the analogue signal into the digital signal D.
The ADC and the DAC operate with the same sampling rate and the same number of bits in each digital number. State the effect on the transmitted analogue signal when, for the ADC and the DAC,
the sampling rate is increased,
the number of bits in each digital number is increased.
