(Papers) CISCE : Download Class XII Exam Papers-2018 (COMPUTER SCIENCE)
COMPUTER SCIENCE :
Subject : COMPUTER SCIENCE
Year : 2018
Class : 12
Duration : 3 Hour
Answer all questions in Part I (compulsory) and six questions from Part-II, choosing two questions from Section-A, two from Section-B and two from Section-C .
All working, including rough work, should be done on the same sheet as therest of the answer.
The intended marks for questions or parts of questions are given in brackets [ ].
(a) State the law represented by the following proposition and prove it with the help of a truth table: 
P V P = P
(b) State the Principle of Duality. 
(c) Find the complement of the following Boolean expression using De Morgan’s law: 
F(a,b,c) = (bʹ + c) + a
(d) Draw the logic diagram and truth table for a 2 input XNOR gate. 
(e) If (~P => Q) then write its: