ISRO2020-66

Question

The following circuit compares two $2$-bit binary numbers, $X$ and $Y$ represented by $X_1X_0$ and $Y_1Y_0$ respectively. ($X_0$ and $Y_0$ represent Least Significant Bits)

Under what conditions $Z$ will be $1$?

• A. $X>Y$
• B. $X<Y$
• C. $X=Y$
• D. $X!=Y$

Comments

correct

Answer 1

Ans: a) X > Y

The function Z can be represented as:

$Z = X_1.Y_1' + (X_1 \odot Y_1).(X_0.Y_0')$

The first term, $X_1.Y_1'$ would be 1 only when $X_1 > Y_1$

The second term would be 1 when $X_1 == Y_1$ and $X_0 > Y_0$

Answer 2

The output equation will be $(X_1⊙Y_1).(X_0.\overline{Y}_0)+X_1.\overline{Y}_1$

Clearly, when $X=0$, ie, when $X_0$ and $X_1$ are both $0$, output can't be 1.

 

So, Options B, C and D are incorrect, because in them, $X=0$ is valid.

Option A

Answer 3

The The rhe the conditions ZZ will be 1 is X>Y

THEREFORE:

OPTION A)