An analogue signal is to be transmitted in digital form. The transmission system may be represented in block form as in [Figure 4.1]. The variation with time t of part of the input analogue signal is shown in [Figure 4.2]. The analogue signal is sampled at time intervals of 0.10ms. The first sample is taken at time t = 0. Some values of the sampled analogue signal and the corresponding digital signals are shown in [Table 4.1]. Each digitised number contains four bits.

1. (a)State two advantages of the transmission of data in digital, rather than analogue, form.[2]
2. (b)(i)In [Table 4.1], underline the least significant bit (LSB) in the digital signal for the time of 0.20 ms.[1]
3. (b)(ii)Complete [Table 4.1].[3]
4. (c)A single bit from the output of the digital-to-analogue converter corresponds to an output analogue signal of 1.0 mV. Assume that the conversion and transmission do not introduce a time delay. On the axes of [Figure 4.3], show the variation with time t of the output from the digital-to-analogue converter.[3]

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