CBSE Guess > Papers > Important Questions > Class XII > 2010 > Computer Science > Computer Science By Ravi Kiran

CBSE CLASS XII

OR

Algebraic Verification:
X+X.Y =X
X.1+X.Y =X
X.(1+Y) =X
X.1 =X
X =X

OR

X.(X+Y) =X
XX+X.Y =X
X.1+X.Y =X
X.(1+Y) =X
X.1 =X
X =X

OR

X+X’. Y =X+Y
(X+X’)(X+Y) =X+Y
1.(X+Y) =X+Y
X+Y =X+Y

OR

X(X’+Y) =X.Y
XX’+X.Y =X.Y
0+X.Y =X.Y
X.Y =X.Y

OR

(b) U.V’+U’.V+U’.V

(c) (X+Y'+Z)(X'+Y+Z).(X'+Y'+Z)(X'+Y'+Z')

(d) A'B' A'B A.B A.B'
C'D' 1 0 1 4 12 8
C'D 1 1 1 5 13 9
C.D 1 3 7 1 15 1 11
C.D' 1 2 6 14 1 10
C'D' C'D C.D C.D'
A'B' 1 0 1 1 1 3 1 2
A'B 1 4 1 5 7 6
A.B 12 13 1 15 14
A.B' 8 9 1 11 1 10
F(A,B,C,D)=A’C’+B’.C+A.C.D

Note: Deduct ½ Mark for extra redundant term/groupings

7. (a) Coaxial Cable: Comparatively Slow, Economic, convenient to lay down,
used in Bus topology of networks; Optical Fibre: Very fast, expensive, reliable, no interference

(b) Hyper Text Markup Language Global System for Mobile communication

(c) eXtensible Markup Language: It contains user defined tags Hyper Text Markup Language: It contains predefined tags.

OR

(d) Cookies: A small piece of information that a server sends to a client When you visit a Web site with cookie capabilities, its server sends certain information about you to your browser, which is stored on your hard drive as a text file. At some later time (such as returning to the site the next day), the server retrieves the cookie. It’s a way toi the server to remember things about you. Firewall: Any of a number of security schemes (hardware/software) that prevent unauthorized users from gaining access to a computer network or that monitor transfers of information to and from the network.

(e) (e1) 1 Mark to every one irrespective of attempt
(e2) Wing Z as it has largest number of computers
(e3) (Full 1 Mark for mentioning Switch/Hub placement in each of the building)

OR

(Full 1 Mark for suggesting the placement of repeater for the distances higher than 70 m)
(e4) TCP/IP Dial Up

OR

Telephone Link

Paper By Mr. Ravi Kiran
Email Id : [email protected]