Download Aptitude Crack
img not found img not found

Exam Questions Papers - Engineering

Q1:

The circuit shown in the figure has 4 boxes each described by inputs P, Q, R and outputs Y, Z with
Y = P ⊕ Q ⊕ R, Z = RQ + P R + Q P

The circuit is a

A 4 bit adder giving P + Q

B 4 bit subtractor giving P - Q

C 4 bit subtractor giving Q - P

D 4 bit adder giving P + Q + R

ANS:B - 4 bit subtractor giving P - Q

Let P = 1101 Q = 1101 Yn = Pn ⊕ Qn ⊕ Rn Z = Rn Qn + Pn Rn + Qn Pn Constructing truth table So that, Rn + 1 = Zn 1 ≥ n ≥ 3 Z4 = R5(MSB) Hence, output is 00010 which show that it is a 4 bit subtractor giving P - Q.