ESAT Forouzan - Chapter 10: Error Detection and Correction

Question 1

Which error detection method consists of a parity bit for each data unit as well as an entire data unit of parity bits?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. Checksum

Answer 1

b. Two-dimensional parity check

Question 2

Which error detection method uses ones complement arithmetic?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. Checksum

Answer 2

d. Checksum

Question 3

Which error detection method consists of just one redundant bit per data unit?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. Checksum

Answer 3

a. Simple parity check

Question 4

Which error detection method involves polynomials?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. Checksum

Answer 4

c. CRC

Question 5

Which of the following best describes a single-bit error?
a. A single bit is inverted.
b. A single bit is inverted per data unit.
c. A single bit is inverted per transmission.
d. Any of the above

Answer 5

b. A single bit is inverted per data unit.

Question 6

If the ASCII character G is sent and the character D is received, what type of error is this?
a. Single-bit
b. Multiple-bit
c. Burst
d. Recoverable

Answer 6

c. Burst

Question 7

If the ASCII character H is sent and the character I is received, what type of error is this?
a. Single-bit
b. Multiple-bit
c. Burst
d. Recoverable

Answer 7

a. Single-bit

Question 8

In cyclic redundancy checking, what is the CRC?
a. The divisor
b. The quotient
c. The dividend
d. The remainder

Answer 8

d. The remainder

Question 9

In cyclic redundancy checking, the divisor is _______ the CRC.
a. The same size as
b. 1 bit less than
c. 1 bit more than
d. 2 bits more than

Answer 9

c. 1 bit more than

Question 10

If the data unit is 111111, the divisor 1010, and the remainder 110, what is the dividend at the receiver?
a. 111111011
b. 111111110
c. 1010110
d. 110111111

Answer 10

b. 111111110

Question 11

If the data unit is 111111 and the divisor 1010, what is the dividend at the transmitter?
a. 111111000
b. 1111110000
c. 111111
d. 1111111010

Answer 11

a. 111111000

Question 12

If odd parity is used for ASCII error detection, the number of 0s per 8-bit symbol is _______.
a. Even
b. Odd
c. Indeterminate
d. 42

Answer 12

b. Odd

Question 13

The sum of the checksum and data at the receiver is _______ if there are no errors.
a. -0
b. +0
c. The complement of the checksum
d. The complement of the data

Answer 13

a. -0

Question 14

The Hamming code is a method of _______.
a. Error detection
b. Error correction
c. Error encapsulation
d. (a) and (b)

Answer 14

d. (a) and (b)

Question 15

In CRC there is no error if the remainder at the receiver is _______.
a. Equal to the remainder at the sender
b. Zero
c. Nonzero
d. The quotient at the sender

Answer 15

b. Zero

Question 16

In CRC the quotient at the sender _______.
a. Becomes the dividend at the receiver
b. Becomes the divisor at the receiver
c. Is discarded
d. Is the remainder

Answer 16

c. Is discarded

Question 17

Which error detection method involves the use of parity bits?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. (a) and (b)

Answer 17

d. (a) and (b)

Question 18

Which error detection method can detect a single-bit error?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. All of the above

Answer 18

d. All of the above

Question 19

Which error detection method can detect a burst error?
a. The parity check
b. Two-dimensional parity check
c. CRC
d. (b) and (c)

Answer 19

d. (b) and (c)

Question 20

At the CRC generator, _______ added to the data unit before the division process.
a. 0s are
b. 1s are
c. The polynomial is
d. The CRC remainder is

Answer 20

a. 0s are

Question 21

At the CRC generator, _______ added to the data unit after the division process.
a. 0s are
b. 1s are
c. The polynomial is
d. The CRC remainder is

Answer 21

d. The CRC remainder is

Question 22

At the CRC checker, _______ means that the data unit is damaged.
a. A string of 0s
b. A string of 1s
c. A string of alternating 1s and 0s
d. A nonzero remainder

Answer 22

d. A nonzero remainder