A full adder can be realised usinga.two half adders, two OR gatesb.none of thesec.two half adders, one OR gated.one half adder, two OR gates

To realize a full adder, we need to understand its components and their connections.

A full adder is a digital circuit that adds three binary inputs: A, B, and a carry-in (Cin), and produces a sum (S) and a carry-out (Cout).

To implement a full adder, we can use either two half adders or one half adder and two OR gates.

Let's consider the options:

a) Two half adders and two OR gates:

• The first half adder takes inputs A and B and produces a partial sum (PS) and a carry-out (Cout1).
• The second half adder takes inputs PS and Cin and produces the final sum (S) and a carry-out (Cout2).
• The two carry-out signals (Cout1 and Cout2) are then connected to two OR gates, which produce the final carry-out (Cout).

b) None of these: This option is not valid as it does not provide a correct implementation of a full adder.

c) Two half adders and one OR gate:

• The first half adder takes inputs A and B and produces a partial sum (PS) and a carry-out (Cout1).
• The second half adder takes inputs PS and Cin and produces the final sum (S) and a carry-out (Cout2).
• The carry-out signals (Cout1 and Cout2) are then connected to one OR gate, which produces the final carry-out (Cout).

d) One half adder and two OR gates:

• This option is not valid as it does not provide a correct implementation of a full adder.

Therefore, the correct answer is option c) - a full adder can be realized using two half adders and one OR gate.