ISRO CSE 2014 PYQ

The absorption identity is X + XY = X, while X' + XY simplifies by distributivity to (X'+X)(X'+Y) = 1$\cdot (X'+Y) = X'+Y$. This is not generally equal to Y (for $X=1,Y=0$, the left side is 0 and the right side is 0; but for $X=0,Y=0$, left side is 1 and right side is 0). The other three expressions are standard valid Boolean identities. Therefore X' + XY = Y is invalid.

The mask 255.255.248.0 is /21. The third octet advances in blocks of 256-248 = 8. Starting at 32, the covered third-octet values are 32 through 39, and the fourth octet can range from 0 through 255. Therefore 205.16.39.44 belongs to this supernet; the other listed addresses fall outside it.

A Turing machine can halt and accept, halt and reject, or run forever (loop without halting). In the standard definition, it does not have “halt by changing the input” as a distinct outcome; the input is read and the machine changes its tape/work configuration according to transitions. Hence that option is the false statement.

Traditional HTTP web browsing uses TCP port 80. TCP provides a reliable, ordered byte stream for HTTP/1.0 and HTTP/1.1. Modern HTTP/3 instead runs over QUIC on UDP port 443, and HTTPS commonly uses TCP port 443 for HTTP/1.1 or HTTP/2. Given the conventional HTTP context and choices, TCP, 80 is the intended answer.