Parabolic antenna is used for_____________ communication.

• A) Microwave
• B) Infrared waves
• C) Radio waves
• D) Light wave

In order to find the location of two errors in an eight bit stream, we have to see _____ different combinations.

• A) 4
• B) 8
• C) 28
• D) 16

Error correction is more ____________ than the error detection.

• A) Difficult
• B) Informal
• C) Easy
• D) Useless

The purpose of adding redundant bits in block coding is

• A) to improve the efficiency of data transmission
• B) to increase the size of data words
• C) to decrease the size of codewords
• D) to provide error detection and correction capability

The _________ is the number of signal elements sent per unit time.

• A) Period
• B) Signal rate
• C) Data rate
• D) Bit rate

Error detection and correction are the services provided by _________ layer.

• A) Application layer
• B) Data link layer
• C) Physical layer
• D) Session layer

PAP and CHAP are used by ____________ as Authentication Protocols.

• A) TCP/ IP
• B) PPP
• C) ICMP
• D) SMTP

To control and manage the transfer of data, a protocol called Point to Point Protocol (PPP) is used at the _________________ layer.

• A) Data link
• B) Physical
• C) Presentation
• D) Network

In digital communication, why do we use a checksum for error detection in a message?

• A) To encrypt the data
• B) To facilitate faster data transmission
• C) To ensure even or odd parity
• D) To correct errors

___________ is an Authentication Protocol, which uses two-step process to authenticate user information.

• A) PAP
• B) LCP
• C) CHAP
• D) ICMP

The flag in PPP is a byte that needs to be ____________ whenever it appears in the data section of the frame.

• A) Duplicated
• B) Blocked
• C) Cleaned
• D) Escaped

In character oriented protocol, each character of frame is encoded using---------- coding system.

• A) Unicode
• B) Bipolar AMI
• C) NRZ
• D) ASCII

In _________ type of error, two or more bits in the data unit will be changed.

• A) Mono
• B) Single bit
• C) Zero
• D) Burst

Primary purpose of adding redundant bits to transmitted data in error detection and correction is _______

• A) to enhance data encryption
• B) to detect or correct errors
• C) to reduce network congestion
• D) to increase data transmission speed

High-Level Data Link Control (HDLC) defines ________ types of frames to deal with the transfer modes.

• A) Four
• B) Two
• C) Six
• D) Three

______________ is the Hamming distance between the binary strings '01001' and '10001.'

• A) 1
• B) 2
• C) 3
• D) 0

The Hamming distance measure _______ in the context of error control coding

• A) the time taken for data transmission
• B) the frequency of data errors
• C) the number of differences between two codewords
• D) the strength of encryption

Payload field of the PPP frame is of variable size and it can carry maximum data up to ____________.

• A) 100 bytes
• B) 1500 bytes
• C) 500 bytes
• D) 10 bytes

In block coding, how is the length of codewords (n) related to the length of data words (k)?

• A) n = k
• B) n < k
• C) n > k
• D) n = 2k

Redundancy contribute to error detection by _______

• A) encrypting data for secure transmission
• B) increasing the speed of data transmission
• C) reducing the size of data frames
• D) adding extra bits to create relationships for error detection