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The logic circuit given below converts a binary code $y1, y2, y3$ into 1. Excess-3 code
2. Gray code
3. BCD code
4. Hamming code
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+2

1. Gray code because B1  = G1 , B2 = G1 exor G2 , B3 = G2 exor G3 , so y is Gray code

Y X
000 000
001 001
010 011
011 010
100 111
101 110
110 100
111 101

$X$ is a GRAY code as for consecutive numbers the change in bit position is only 1.

From Wikipedia,

More formally, a Gray code is a code assigning to each of a contiguous set of integers, or to each member of a circular list, a word of symbols such that each two adjacent code words differ by one symbol. These codes are also known as single-distance codes, reflecting the Hamming distance of 1 between adjacent codes. There can be more than one Gray code for a given word length, but the term was first applied to a particular binary code for the non-negative integers, the binary-reflected Gray code, or BRGC, the three-bit version of which is shown above.

So, the given code is not GRAY code as the codes for 3-4, as well as 7-0 differs by 2 bits and not 1. It is also neither BCD (same as binary for 3 bits) nor Excess-3. So, answer should be none of these.

by Veteran (425k points)
selected
+1
when we go from 010 to 111. There is a change of two bits in X column.
+1
 Binary Gray 000 000 001 001 010 011 011 010 100 110 101 111 110 101 111 100
+2

@ Arjun sir, gray code for 100 is 110 but the circuit will give 111 as o/p for the i/p 100. Then how the answer will be gray code?

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@vandana There can be more than one GRAY code for a given word length. But as rohini pointed out, this is not Gray code. I have corrected..
+1
Thank you sir.
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sir it simply a conversion from grey to binary na ? if they mention binary code then is it true ?
 Y X 110 100 000 000 001 001 111 101 100 111 010 011 011 010 101 110

X is gray Code.

Hence, Answer is B. Gray code

by (15 points)
+1
Then simply make a circuit which does nothing but takes the same output and input a GRAY code to it and say the circuit produces a GRAY code :)
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0
No, the gray code should be produced for the input sequence 000, 001, 010 ...
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the given circuit is conversion of gray code to binary codes
–1 vote
Ans is c but in isro key answer is b.

Because for gray code no output take as a input but her it is given so it is not gray code

In bcd code we take output as a input for next gate other then most significant bit
by (45 points)
0

In question according to gray code representation y2 is connected to 2nd exor in place of x2

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In BCD , each digit is represented by its binary equivalent. So  BCD for 100 (4) should be 100. But circuit represents 111 for 100.
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M etna to nhi jaanta but for gray code In question y2 is connected to 2nd exor in place of x2