Page 680 - Computer science 868 Class 12
P. 680
(a) What is the expression or statement at ?1? [1]
(b) What is the expression or statement at ?2? [1]
(c) What is the expression or statement at ?3? [1]
PART II – 50 MARKS
Answer six questions in this part, choosing two questions from Section A, two from Section B and two from Section C.
SECTION – A
Answer any two questions.
Question 3.
(i) The National College of Journalism is offering courses in three different categories of [5] journalism, which are the print, the
web and the broadcasting media. A student is eligible to apply if he/she satisfies any one of the following conditions:-
• The student is a graduate in any discipline with an aggregate percentage of 75 or above and with a record of literary skills.
OR
o The student is a graduate in Mass Communication with an aggregate percentage of 75 above
The inputs are:
A : Graduate in any discipline
B : Graduate in Mass Communication
C : Aggregate percentage less than 75
D : Record of literary skills
Output:
R : Denotes eligible to apply [ 1 indicates Yes and 0 indicates No in all cases]
Draw the truth table for the inputs and outputs given above write the POS expression for R(A,B,C,D)
(ii) Reduce the above expression R(A,B,C,D) by using 4-variable Karnaugh map, showing the various groups (i.e. octal, quads
and pairs). [5]
Draw the logic gate diagram for the reduced expression. Assume that the variables and their complements are available as
inputs.
Question 4.
(i) (a) Given the Boolean function F(A, B, C, D) = Ʃ((0,1,3,4,5,6,7,9,10,11,13,15)
Reduce the above expression by using 4-variable Karnaugh map, showing the various groups (i.e octal, quads and pairs). [4]
(b) Draw the logic gate diagram for the reduced expression. Assume that the variables and their complements are
available as inputs. [1]
(ii) (a) Write the boolean expression of ?1? , ?2? , ?3? and ?4? for the following logic circuit diagram. [4]
(b) Convert the following canonical expression to cardinal form [1]
A.B’.C+A.B.C’+A’.B.C+A’.B’.C’
?1?
?3?
?4?
?2?
Question 5.
(i) Draw the logic circuit diagram to convert hexadecimal numbers A-F to its binary form. Also write the binary equivalent of
the numbers. [5]
(ii) Verify if the following proposition is valid or not using truth table [3]
b → (∼a → b) ↔ c
(iii) Draw the logic circuit diagram of a Full Adder circuit [2]
678678 Touchpad Computer Science-XII

