0 — Test 331

Correct Answer: A. A. Microwave system
Explanation: Microwave System is not a transmission medium. Instead, it is used for the transmission of data over a cable as well as lines. All the others are commonly used transmission media. Coaxial cable is a widely used wire medium, which offers a bandwidth of approximately 750 MHz.

Correct Answer: C. C. Few hundreds of khz to a few ghz
Explanation: Communication through free space using radio waves takes place over a very wide range of frequencies, i.e. from a few hundreds of Hz to a few kHz. This range of frequencies is further subdivided and allocated for various services.

Correct Answer: B. B. Microwaves to ultraviolet
Explanation: Optical communication which is also called optical telecommunication is referring to a type of communication at a distance using light to carry information. Optical communication using fibers is performed in the frequency range of 1 THz to 1000 THz, i.e. microwaves to ultraviolet.

Correct Answer: A. A. True
Explanation: Yes, this is a true statement. The bandwidth of optic fiber is high due to the speed with which data can be transmitted and also the range of frequencies over which the data can travel without any attenuation. An optical fiber can offer a transmission bandwidth in excess of 100 GHz.

Correct Answer: D. D. International telecommunication union
Explanation: The expansion of ITU is the International Telecommunication Union. It is a specialized agency of the United Nations that is responsible for all the matters related to information and communication technologies. The ITU administers the present system of frequency allocations

Correct Answer: A. A. Tcp
Explanation: Since TCP is a reliable protocol, it’s more efficient to use TCP protocol for e-mail transfer. TCP also provides more security than other transport layer protocols.

Correct Answer: A. A. SMTPs
Explanation: SSMTP is a simple mail transfer program to send mail from a local PC to a mail host. SNMP is a network management protocol. STARTTLS connections are secured by TLS.

Correct Answer: D. D. 25
Explanation: Port 21 is used for FTP control connection, port 22 is used by SSH, and port 23 is used by TELNET.

Correct Answer: D. D. FTP
Explanation: FTP is used to share files. SMTP, POP and IMAP are the protocols used to send and receive mails on the internet.

Correct Answer: B. B. An smtp extension
Explanation: ODMR is an extension to SMTP, in which mails are relayed to the receivers after they are authenticated. It allows only the authorized receivers to receive the mail.