MCQ: In a linear block code, the exclusive OR (XOR) of any two valid

code words creates

A. valid codeword
B. invalid codeword
C. valid data
D. invalid data

Answer 
MCQ: There is no error in the received code word, if the syndrome is

A. maximum
B. minimum
C. 0
D. 1

Answer 
MCQ: A simple parity-check code has dmin =

A. 0
B. 1
C. 2
D. 3

Answer 
MCQ: A simple parity-check code can detect

A. odd number of errors

B. even number of errors
C. positive number of errors
D. negative number of errors
 Answer 
MCQ: A simple parity-check code is the most familiar

A. error-correcting code
B. error-detecting code
C. dataword
D. Both A& B

Answer 
 For a (6,4) block code where n = 6, k = 4 and dmin = 3, how many errors can be
corrected by this code?

a. 0
b. 1
c. 2
d. 3
Answer b

6)   Which amount the following is capable of correcting any combination of three or

fewer errors random errors in a block of 23 bits?

a. Hamming codes
b. Interleaved code
c. Repetition codes
d. Golay code
Answer D

7)   The minimum distance of linear block code (dmin) is equal to minimum number of
rows or columns of HT, whose  _____ is equal to zero vector.

a. sum
b. difference
c. product
d. divison
Answer  Explanation 
ANSWER: sum
Explanation:
No explanation is available for this question!

8)   In a linear code, the minimum Hamming distance between any two code words is
______minimum weight of any non-zero code word.

a. Less than
b. Greater than
c. Equal to
d. None of the above
Answer  Explanation  c

9)   Which among the following represents the code in which codewords consists of
message bits and parity bits separately?

a. Block Codes
b. Systematic Codes
c. Code Rate
d. Hamming Distance
Answer  Explanation  b

10)   Which among the following is/are the essential condition/s for a good error control
coding technique?

a. Faster coding & decoding methods

b. Better error correcting capability
c. Maximum transfer of information in bits/sec
d. All of the above
Answer  Explanation d
How many bits in the data unit has changed in single bit error?

A. only 1
B. two bits
C. three bits
D. four bits

Answer 
MCQ: To guarantee the detection of up to s errors in all cases, the
minimum hamming distance in a block code must be

A. s
B. s+1
C. s-1
D. 0

Answer 
MCQ: The cyclic codes are fast when these are implemented in

A. software
B. hardware
C. Local area network
D. Both A and B

Answer 
MCQ: In block coding, we divide our message into blocks, is called

A. code blocks
B. packet blocks
 C. code words
D. datawords

Answer 
MCQ: Find the parity bit for 1001011

A. 0
B. 1
C. 2
D. None

Answer
The correct answer for each question is indicated by a  .

1 INCORRECT Which error detection method uses one's complement arithmetic?

A)Simple parity check

B)Two-dimensional parity check

C)CRC

D)Checksum

Which error detection method consists of just one redundant bit per data
2 INCORRECT
unit?

A)Simple parity check

B)Two-dimensional parity check

C)CRC

D)Checksum
3 INCORRECT In cyclic redundancy checking, what is the CRC?

A)The divisor

B)The quotient

C)The dividend

D)The remainder

In cyclic redundancy checking, the divisor is _______ the CRC.

4 INCORRECT

A)The same size as

B)one bit less than

C)one bit more than

D)none of the above

5 INCORRECT A burst error means that two or more bits in the data unit have changed.

A)double-bit

B)burst

C)single-bit

D)none of the above

In ________ error correction, the receiver corrects errors without

6 CORRECT
requesting retransmission.

A)backward

B)onward
 C)forward

D)none of the above

In ________ error correction, the receiver asks the sender to send the data
7 INCORRECT
again.

A)backward

B)retransmission

C)forward

D)none of the above

We can divide coding schemes into two broad categories: ________ and
8 INCORRECT
______coding.

A)block; linear

B)linear; nonlinear

C)block; convolution

D)none of the above

9 INCORRECT In modulo-2 arithmetic, __________ give the same results.

A)addition and multiplication

B)addition and division

C)addition and subtraction

D)none of the above

 In modulo-2 arithmetic, we use the ______ operation for both addition and
1 CORRECT subtraction.
0
A)XOR

B)OR

C)AND

D)none of the above

In _____ coding, we divide our message into blocks, each of k bits, called
1 UNANSWERED ___.
1
A)block; blockwords

B)linear; datawords

C)block; datawords

D)none of the above

We add r redundant bits to each block to make the length n = k + r. The

1 UNANSWERED resulting n-bit blocks are called _________.
2
A)datawords

B)blockwords

C)codewords

D)none of the above

The ________ between two words is the number of differences between

1 UNANSWERED corresponding bits.
3
A)Hamming code

B)Hamming distance
 C)Hamming rule

D)none of the above

1 UNANSWERED
To guarantee the detection of up to 5 errors in all cases, the minimum
Hamming distance in a block code must be _______.
4
A)5

B)6

C)11

D)none of the above

1 UNANSWERED
To guarantee correction of up to 5 errors in all cases, the minimum
Hamming distance in a block code must be ________.
5
A)5

B)6

C)11

D)none of the above

1 UNANSWERED
In a linear block code, the _______ of any two valid codewords creates
another valid codeword.
6
A)XORing

B)ORing

C)ANDing

D)none of the above

1 UNANSWERED
A simple parity-check code can detect __________ errors.

7
 A)an even-number of

B)two

C)no errors

D)an odd-number of

_______codes are special linear block codes with one extra property. If a
1 UNANSWERED codeword is rotated, the result is another codeword.
8
A)Non-linear

B)Convolution

C)Cyclic

D)none of the above

The _____of errors is more difficult than the ______.

1 UNANSWERED
9
A)correction; detection

B)detection; correction

C)creation; correction

D)creation; detection

In modulo-11 arithmetic, we use only the integers in the range ______,

2 UNANSWERED inclusive.
0
A)1 to 10

B)1 to 11

C)0 to 10

D)none of the above

2 UNANSWERED
In modulo-2 arithmetic, we use only ______.

1
A)1 and 2

B)0 and 2

C)0 and 1

D)none of the above

2 UNANSWERED
Adding 1 and 1 in modulo-2 arithmetic results in _________.

2
A)1

B)2

C)0

D)none of the above

2 UNANSWERED
In block coding, if k =2 and n =3, we have _______ invalid codewords.

3
A)8

B)4

C)2

D)none of the above

2 UNANSWERED
The Hamming distance between equal codewords is _________.

4
A)1

B)n

C)0
 D)none of the above

2 INCORRECT
The Hamming distance between 100 and 001 is ________.

5
A)2

B)0

C)1

D)none of the above

2 INCORRECT
In block coding, if n = 5, the maximum Hamming distance between two
codewords is ________.
6
A)2

B)3

C)5

D)none of the above

2 UNANSWERED
If the Hamming distance between a dataword and the corresponding
codeword is three, there are _____ bits in error.
7
A)3

B)4

C)5

D)none of the above

2 CORRECT
The _______ of a polynomial is the highest power in the polynomial.

8
 A)range

B)degree

C)power

D)none of the above

2 CORRECT
The divisor in a cyclic code is normally called the _________.

9
A)degree

B)generator

C)redundancy

D)none of the above

3 INCORRECT
A generator that contains a factor of ____ can detect all odd-numbered
errors.
0
A)x

B)x + 1

C)1

D)none of the above

3 UNANSWERED
Checksums use _________ arithmetic.

1
A)two's complement arithmetic
 B)one's complement arithmetic

C)either (a) or (b)

D)none of the above

3 UNANSWERED
In one's complement arithmetic, if positive 7 is 0111, then negative 7 is
________.
2
A)1111

B)1101

C)1000

D)none of the above

3 CORRECT
The checksum of 1111 and 1111 is _________.

3
A)1111

B)0000

C)1110

D)0111

3 INCORRECT
The checksum of 0000 and 0000 is __________.

4
A)1111

B)0000

C)1110

D)0111