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Phrases Boolean Algebra PYQ



Which one of the following Boolean algebraic rule is correct?





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Solution

A + A'B = (A + A') . (A + B)
             =  1 . (A + B) 
             = A + B



Which term is redundant in the expression AB + A'C + BC ?





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Solution



The total number binary function that can be defined using n Boolean variables is





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Solution

✅ Given Information:

We are asked to find the total number of binary functions that can be defined using n Boolean variables.

✅ Step 1: Number of input combinations:

For n Boolean variables, the number of possible input combinations is 2n.

✅ Step 2: Number of possible outputs:

Each input combination can map to either 0 or 1, so there are 2 possible outputs for each of the 2n input combinations.

✅ Final Formula:

Total Binary Functions = 2(2n)

✅ Final Answer:

The total number of binary functions that can be defined using n Boolean variables is: 2(2n)



Assume x' represents negation of x the Boolean function x'y' + xy + x'y is equivalent to?





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Solution



The equivalence of given expression x+x'y with Boolean theorem is….





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Solution

x+x'y
=(x+x')(x+y)
=(x+y)


Consider the following minterm for F:F(P, Q, R, S) = Σ0, 2, 5, 7, 8, 10, 13, 15. The minterms 2, 7, 8, and 13 are don't care terms. The minimal sum of products form for F is





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Solution



Cosider the following Boolean Expression for F:
F(P,Q,R,S)=PQ+¯PQR+¯PQ¯RS
The minimum sum of products form of F is





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Solution



The number of minterms in a n variable truth tableis





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Solution

✅ Number of Minterms in a n-variable Truth Table:

For n Boolean variables, the number of possible combinations of inputs is:

2n

Each combination corresponds to one minterm. Therefore, the total number of minterms in the truth table is also 2n.

✅ Final Answer:

The number of minterms in a n-variable truth table is: 2n



Let and denote the Exclusive - OR and Exclusive-NOR operations respectively. Which of the following is not correct?





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Solution



The reduced form of the Boolean function F = xyz + xyz' + x'y'z + xy'z is





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Solution



How many Boolean expressions can be formed with 3 Boolean variables? 






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Solution



Any given truth table can be represented by





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Solution



The expression P+QR is the reduced form of _____





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Solution

Boolean Simplification

Given Expression: P + QR

We ask: This is the simplified (reduced) form of which expression?

Try expanding: (P + Q)(P + R)

Using distributive law:

(P + Q)(P + R) = P(P + R) + Q(P + R) = P + PR + PQ + QR = P + PQ + PR + QR = P + QR (since P absorbs PQ and PR)

✅ Final Answer: (P + Q)(P + R)



The Boolean expression for the following truth table is _________
 x y z f
 0 0 0 0
 0 0 1 0
 0 1 0 1
 0 1 1 0
 1 0 0 0
 1 0 1 1
 1 1 0 0
 1 1 1 1





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Solution



The minimum number of NAND gates required for implementing the Boolean expression AB+A¯BC+A¯B¯C





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Solution

AB+A¯BC+A¯B¯C
=AB+ABC+ABC
=AB+AB(C+C)
=AB+AB
=A(B+B)
=A



Which of the following is equivalent to the Boolean expression: 
(X+Y).(X+¯Y).(¯X+Y)





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Solution

(X+Y).(X+¯Y).(¯X+Y)
=(X+Y)(X+Y)(X+Y)
=(XX+XY+YX+YY)(X+Y)
=(X+XY)(X+Y)
=X(1+Y)(X+Y)
=X(X+Y)
=XX+XY
=XY


Write the simplified form of the Boolean expression
(A+C)(AD+AD')+AC+C





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Solution

(A+C)(AD+AD')+AC+C
=(A+C)A(D+D')+C(A+1)
=(A+C)+C
=A+C


The Boolean expression AB+ AB' + A'C + AC is unaffected by the value of the Boolean variable





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Solution

A(B+¯B)+C(A+¯A)A+C


If a signal passing through a gate is inhibited by sending a low into one of the inputs, and the output is HIGH, the gate is a(n):





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Solution

Output is high if any of the input is low. The truth table for NAND gate is:
 AOutput 
 0 0
 0 1 1
 1 0 1
 1 1 1
Table representing NAND Gate.


The number of terms in the product of sums canonical form of  is





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Solution



Consider the following min term expression for F.
F(P,Q,R,S) = ∑ (0, 2, 5, 7, 8, 10, 13, 15)
The minterms 2, 7, 8 and 13 are ‘do not care' terms. 
The minimal sum of products form for F is





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Solution



The Boolean expression represented by the following Venn diagram is






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Solution



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