CompTIA Network+ Question A-2

An administrator notices an unused cable behind a cabinet that is terminated with a DB-9 connector. Which of the following protocols was MOST likely used on this cable?

A. RS-232
B. 802.3
C. ATM
D. Token ring

Correct Answer: A

Explanation:
A DB-9 connector is used on serial cables. Serial cables use the RS-232 protocol which defines the functions of the 9 pins in a DB-9 connector. The RS-232 standard was around long before computers. It’s rare to see a new computer nowadays with a serial port but they were commonly used for connecting external analog modems, keyboards and mice to computers.

CompTIA A+ Question F-72

A technician is tasked with adding a Barcode Scanner to a user PC. Which of the following would MOST likely be used to make the connection to the PC? (Select TWO).

A. RJ-45
B. Serial port
C. USB
D. DB-15
E. Infrared

Correct Answer: BC

CompTIA A+ Question F-61

After installing a new serial port card in a computer, the communication parameters need to be configured. Which of the following is the MOST common communication configuration for a serial port?

A. Eight data bits, even parity, two stop bits
B. Seven data bits, no parity, one stop bit
C. Eight data bits, no parity, one stop bit
D. Seven data bits, even parity, one stop bit

Correct Answer: C

Explanation:
http://www.modemhelp.net/faqs/8n1.shtml

CompTIA A+ Question D-26

Which of the following settings for a serial port expansion card is the default for MOST external modems?

A. 6, Yes, 0
B. 6, None, 1
C. 8, None, 1
D. 8, Yes, 0

Correct Answer: C