| a. |
Show
how NAND gates can be used to construct
i)
a NOT gate
ii)
an AND gate
iii)
an OR gate
iv)
a NOR gate.
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4
marks |
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| b. |
Draw
a truth table for an exclusive OR (EOR) gate. |
1
marks |
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| c. |
What
is meant by a half-adder? Sketch to show the internal construction of a
half-adder. Verify the correctness of your drawing by using a truth table. |
6
marks |
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A half-adder adds two binary digits and gives the sum and
the carry bits. |
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| d. |
What
is meant by a full-adder? Explain how a full-adder can be constructed from
two half-adders and an OR gate. |
5
marks |
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A fuller-adder adds three bits to give a sum and a carry
bit. |
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