The logic circuit given in the figure is equivalent to:

The correct answer is Option (4) → AND gate

The first gate in the figure is a NAND gate (an AND gate with a small circle at its output) and its output Y′ feeds a NOT gate. In Boolean form the NAND output is the inverse of the product, \( Y' = \overline{A\cdot B} \).

The NOT gate inverts it again, and a double inversion gives back the original:

    \( Y = \overline{Y'} = \overline{\overline{A\cdot B}} = A\cdot B \)

The output is 1 only when both A and B are 1, which is the AND operation.

Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), and it also appears to be out of the CUET 2026 syllabus.

NCERT (Pre-rationalised edition, 2022-23):
NOT Gate – “This is the most basic gate, with one input and one output. It produces a ‘1’ output if the input is ‘0’ and vice-versa. That is, it produces an inverted version of the input at its output.”

NAND Gate – “This is an AND gate followed by a NOT gate. If inputs A and B are both ‘1’, the output Y is not ‘1’.”