Which protocol is used for email communication?

• SMTP

• TCP

• FTP

• HTTP

Answer explanation

The correct answer is SMTP. SMTP stands for Simple Mail Transfer Protocol, which is the standard protocol for sending emails across the Internet. It works closely with something called the Mail Transfer Agent (MTA) to send your communication to the right computer and email inbox. Other options like TCP, FTP, and HTTP are protocols used for different purposes, not specifically for email communication.

Which network topology connects all devices in a linear sequence?

• Bus topology

• Star topology

• Ring topology

• Mesh topology

Answer explanation

The question asks about the network topology that connects all devices in a linear sequence. The correct answer is Bus topology. In a bus topology, all devices are connected to a single central cable, known as the bus. Therefore, it forms a linear sequence of connected devices, unlike the other options.

Which network device operates at the Data Link layer of the OSI model?

• router

• hub

• firewall

• switch

Answer explanation

The Data Link layer of the OSI model is responsible for node-to-node communication and error detection in network frames. A switch operates at this layer. It uses MAC addresses to forward data to the correct destination, unlike a router (network layer), a hub (physical layer), or a firewall (application layer).

Which security measure prevents unauthorized access to a network?

• firewall

• encryption

• password protection

• antivirus software

Answer explanation

A firewall is a security measure that prevents unauthorized access to a network. It acts as a barrier between a trusted network and an untrusted network, such as the internet. It controls incoming and outgoing network traffic based on predetermined security rules, thus preventing unauthorized access.

Which wireless networking standard operates in the 2.4 GHz frequency band?

• Wi-Fi 4 (802.11n)

• Wi-Fi 6 (802.11ax)

• Bluetooth

• Wi-Fi 5 (802.11ac)

Answer explanation

The question asks about the wireless networking standard that operates in the 2.4 GHz frequency band. The correct answer is Wi-Fi 4 (802.11n). This is because Wi-Fi 4 (802.11n) is a wireless networking standard that operates in the 2.4 GHz frequency band, unlike the other options provided.

Which protocol is used to resolve IP addresses to domain names?

• DNS

• SMTP

• FTP

• HTTP

Answer explanation

The Domain Name System (DNS) is the protocol used to resolve IP addresses to domain names. It serves to translate human-friendly domain names into the numerical IP addresses needed for locating and identifying computer services and devices. Therefore, DNS is the correct answer to the question.

Which network topology connects all devices to a central device?

• star topology

• mesh topology

• ring topology

• bus topology

Answer explanation

The question asks about the network topology that connects all devices to a central device. The correct answer is 'star topology'. In a star topology, all devices are connected to a central device, typically a hub or switch, allowing for easy addition or removal of devices without disrupting the network. Other topologies like mesh, ring, or bus do not have a central device.

Which network device operates at the Network layer of the OSI model?

• firewall

• hub

• router

• switch

Answer explanation

The Network layer of the OSI model is responsible for packet forwarding including routing through intermediate routers, which is why the correct answer is 'router'. Other devices like firewalls, hubs, and switches operate at different layers of the OSI model.

Which security measure encrypts data transmitted over a network?

• IPsec

• OSPF

• RIP

• TCP/IP

Which wireless networking standard operates in the 5 GHz frequency band?

• 802.11n

• 802.11g

• 802.11a

• 802.11b

Answer explanation

The question asks about the wireless networking standard that operates in the 5 GHz frequency band. The correct answer is 802.11a. This standard is known to operate in the 5 GHz frequency band, unlike the other options provided which operate in different frequency bands.