Digital Electronics - Combinational Logic Analysis - Discussion
Discussion Forum : Combinational Logic Analysis - General Questions (Q.No. 9)
9.
A 4-variable AND-OR-Invert circuit produces a 0 at its Y output. Which combination of inputs is correct?
none of the above
Discussion:
12 comments Page 1 of 2.
Sivaramakrishna said:
1 decade ago
For ex a=0 b=0 c=0 d=0
y=1
How it can give 0 output ?
So answer is D.
y=1
How it can give 0 output ?
So answer is D.
Swarna said:
1 decade ago
Yes my.ex a=0,b=0,c=0&d=0.
a,b is connected to AND1 GATE.c,d is connected to another AND2 GATE.these two AND2 gates connected to OR gate.so AND1 is enable,AND2 is disable.the output of the OR gate is high.these output connected to INVERT ER ,so output is low .
a,b is connected to AND1 GATE.c,d is connected to another AND2 GATE.these two AND2 gates connected to OR gate.so AND1 is enable,AND2 is disable.the output of the OR gate is high.these output connected to INVERT ER ,so output is low .
Himalesh said:
1 decade ago
Take out de swarna`s method.. If input is 1100 output will be 1 after inverted the result.. So we can't determine the answer..
Mukund said:
1 decade ago
Without proper values of the variables how can we get the expression.
Dakshesh patel said:
1 decade ago
Take, A=1, B=1, C=1, D=1.
A, B is connected to AND1 GATE. Output is 1. This output is connected to inverter. So output will be 0.
C, D is connected to AND2 GATE. Output is 1. This output is connected to inverter. So output will be 0.
Now this two output is connected to OR GATE. So output is 0.
Therefore answer C is correct.
A, B is connected to AND1 GATE. Output is 1. This output is connected to inverter. So output will be 0.
C, D is connected to AND2 GATE. Output is 1. This output is connected to inverter. So output will be 0.
Now this two output is connected to OR GATE. So output is 0.
Therefore answer C is correct.
Satish said:
1 decade ago
Take, A=1, B=0, C=1, D=0.
Then we are getting output as 1.
So, answer C is wrong.
Then we are getting output as 1.
So, answer C is wrong.
Jeya said:
1 decade ago
Answer C is correct. Because,
A'B'+CD=Y'=Y.
Take A=1,B=1,C=1 and D=1.
A'=0,B'=0 is connected to AND gate-1, C=1, D=1 is connected to AND gate-2. i.e A'B'=0, CD=1. Outputs of and gate are given to OR gate. i.e 0+1=1. Output is connected to inverter. Hence the output Y=0.
A'B'+CD=Y'=Y.
Take A=1,B=1,C=1 and D=1.
A'=0,B'=0 is connected to AND gate-1, C=1, D=1 is connected to AND gate-2. i.e A'B'=0, CD=1. Outputs of and gate are given to OR gate. i.e 0+1=1. Output is connected to inverter. Hence the output Y=0.
Mahendar said:
1 decade ago
Answer C;
From the problem AND and OR inverts is given, so nand and nor.
A'B'=1, CD=0 for nand, then 01 is zero for nor input.
From the problem AND and OR inverts is given, so nand and nor.
A'B'=1, CD=0 for nand, then 01 is zero for nor input.
Gaurav Chavda said:
9 years ago
All the equation can give 0 output, if we take in input in such a way. Because here no input values are specified/fixed.
AAA said:
8 years ago
Answer C is definitely correct.
A'B'+CD
=00+11
=0+1
=1.
After putting an inverter for 1, it will give us 0 (AND-OR-invert circuit).
A'B'+CD
=00+11
=0+1
=1.
After putting an inverter for 1, it will give us 0 (AND-OR-invert circuit).
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