Page 718 - SUBSEC October 2017_Neat
P. 718
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(iv) By considering the role of feedback in the circuit and the condition for the
type of gate in (e) (ii) to have a logic 0 output, explain why the output does
NOT change when the input changes in the second step of the sequence
(Row 2) as shown in Table 1.
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[3 marks]
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(f) (i) Draw the circuit for a half-adder. Explain, with the aid of a truth table, what
its function is and how it performs that function.
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[5 marks]
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