Chapter 10: Data Communication and Internet Services (Set-7)
In a communication system, the “sender” is the device that
A Receives the data
B Generates the data
C Stores the data
D Blocks the data
The sender is the source that creates the message and starts transmission. It converts the data into signals and sends them through a medium using agreed rules so the receiver can interpret it.
In data communication, the “receiver” is the device that
A Creates the message
B Encrypts the medium
C Routes the protocol
D Accepts the message
The receiver is the destination device that gets the signal, decodes it, and reconstructs the original message. Correct reception depends on matching protocols, timing, and signal quality.
A “protocol” in networking is best described as
A Cable thickness value
B Device brand name
C Rules for exchange
D Data storage method
Protocols define how data is formatted, addressed, transmitted, checked for errors, and acknowledged. They ensure devices made by different vendors can still communicate correctly and reliably.
Which data flow mode supports only one-way communication from source to destination
A Simplex communication
B Half-duplex communication
C Full-duplex communication
D Multi-duplex communication
Simplex is strictly one direction. The receiver cannot transmit back using the same channel, so feedback requires a separate path or different mechanism in the system.
Which mode allows both directions, but one device transmits at a time
A Simplex mode
B Full-duplex mode
C Half-duplex mode
D Broadcast mode
Half-duplex supports two-way communication, but not simultaneously. Devices take turns transmitting, which can reduce performance compared to full-duplex when both sides need to send frequently.
Full-duplex communication means
A Both send simultaneously
B Only receive data
C Only send data
D One-way communication
In full-duplex, both ends transmit and receive at the same time. This avoids waiting turns and improves efficiency, common in modern telephone calls and switched Ethernet links.
Bandwidth refers to the
A Total data stored
B Maximum data capacity
C Number of devices
D Password strength level
Bandwidth is the channel’s capacity to carry data per unit time. Higher bandwidth generally supports higher possible speeds, though actual speed also depends on congestion and signal quality.
Transmission speed commonly means
A Pages per minute
B Volts per second
C Bits per second
D Inches per minute
Speed is measured in bps such as Mbps or Gbps. It represents how fast bits can be transmitted, and is used to compare the performance of network connections.
Noise is best defined as
A Unwanted signal disturbance
B Higher network speed
C Strong encryption method
D Router address list
Noise is unwanted interference that affects signals. It can corrupt data bits, increase errors, and reduce throughput, especially over long cables, wireless links, or electrically noisy environments.
Attenuation in a cable means
A Signal becomes encrypted
B DNS becomes faster
C IP becomes static
D Signal becomes weaker
Attenuation is the loss of signal strength over distance. Higher attenuation can cause errors, so repeaters, amplifiers, or better quality media are used to maintain reliable transmission.
Modulation is mainly used to
A Assign IP address
B Create DNS zones
C Carry data on carrier
D Transfer email files
Modulation changes a carrier wave to encode data by altering amplitude, frequency, or phase. It allows digital data to travel efficiently over wireless and many wired broadband systems.
The OSI model has
A Seven layers
B Four layers
C Five layers
D Two layers
OSI divides network communication into seven layers to standardize functions. It helps understand how data moves from applications down to physical transmission and helps in troubleshooting.
The OSI layer responsible for physical transmission of bits is
A Transport layer
B Session layer
C Physical layer
D Application layer
The Physical layer sends raw bits as electrical, optical, or radio signals. It defines connectors, voltages, frequencies, timing, and the physical characteristics of cables and wireless channels.
In OSI, MAC addressing is mainly handled at
A Network layer
B Data Link layer
C Presentation layer
D Session layer
The Data Link layer uses frames and MAC addresses for delivery within a local network. It also provides error detection and manages how devices share the same physical medium.
The OSI layer that performs routing between networks is
A Network layer
B Physical layer
C Data Link layer
D Presentation layer
The Network layer handles logical addressing and routing, allowing packets to move across multiple networks. Routers operate mainly at this layer to forward packets toward destinations.
TCP/IP model is commonly shown as
A Seven layers
B Three layers
C One layer
D Four layers
The TCP/IP model is often described as Link, Internet, Transport, and Application layers. It matches how real internet protocols are organized and implemented in networks.
Encapsulation means
A Removing all headers
B Blocking all traffic
C Adding protocol headers
D Increasing noise level
Encapsulation wraps data with headers at each layer, such as TCP/UDP and IP headers. These headers carry addressing and control details so networks can route and deliver data correctly.
IP is mainly used for
A Addressing and routing
B Encrypting web pages
C Sending email content
D Assigning IP leases
IP provides logical addresses and forwards packets through routers across networks. It does not guarantee delivery by itself; reliable delivery is normally handled by TCP at a higher layer.
TCP is mainly used when applications need
A Unreliable fast delivery
B Reliable delivery
C Domain name mapping
D Dynamic address leasing
TCP provides reliable, ordered delivery using acknowledgments, sequencing, and retransmissions. It is used in web browsing, file downloads, and email where data accuracy is important.
UDP is commonly used for
A Guaranteed delivery
B DNS zone transfers
C Low-latency traffic
D Server authentication
UDP has low overhead and avoids connection setup, so it suits real-time applications like voice or video. It does not guarantee delivery, so applications handle loss if needed.
HTTP is used primarily for
A Web communication
B Email sending
C IP leasing
D File encryption
HTTP is the main protocol used by browsers and web servers. It supports request/response messaging to fetch pages, images, and data from websites and web applications.
HTTPS differs from HTTP by adding
A DHCP addressing
B DNS caching
C TLS encryption
D UDP delivery
HTTPS uses TLS to encrypt traffic and provide integrity checks. It also relies on certificates to help verify the website identity, making browsing safer for logins and sensitive data.
A URL contains information like
A RAM and CPU
B Protocol and domain
C MAC and TTL
D Cache and lease
A URL typically includes a scheme (http/https), domain name, and path. It tells the browser where to connect and what resource to request from the web server.
HTTP GET is mainly used to
A Assign an IP
B Upload mail files
C Create DNS records
D Retrieve a resource
GET requests fetch data like pages or images. It is generally used for read-only operations, and browsers may cache responses to speed up repeated access.
HTTP POST is mainly used to
A Submit data
B Resolve names
C Trace routing path
D Change subnet mask
POST sends data in the request body, commonly used for form submissions and updates. It can carry larger data than GET and is used when server-side data may change.
HTTP status 200 means
A Page missing
B Forbidden access
C Request successful
D Server error
A 200 response indicates the server successfully processed the request and returned the resource. This is the typical status for normal page loads when content is available.
HTTP status 404 means
A Request successful
B Resource not found
C Temporary redirect
D Authentication required
404 indicates the server cannot find the requested resource at the given URL. The server is reachable, but the page or file does not exist at that location.
Cookies are mainly used to
A Store small state
B Increase bandwidth
C Reduce attenuation
D Replace DNS servers
Cookies store small bits of data in the browser, like session IDs and preferences. They help websites remember users across requests and maintain login state.
DNS is mainly used to
A Transfer files
B Send emails
C Map names to IPs
D Encrypt web pages
DNS translates domain names into IP addresses so devices can connect to servers. Without DNS, users would need to use numeric IP addresses to reach websites.
DHCP is mainly used to
A Assign IP settings
B Encrypt data traffic
C Create web pages
D Transfer email files
DHCP automatically provides IP address, subnet mask, gateway, and DNS settings. It simplifies connecting devices to a network and reduces manual configuration mistakes.
A DHCP lease is
A Permanent IP record
B DNS alias mapping
C Secure web certificate
D Time-limited assignment
A lease gives a device permission to use an IP address for a fixed time. Renewals allow continued use, while expiry helps reuse addresses and avoid long-term conflicts.
Default gateway is used when the destination is
A Inside same subnet
B Only DNS server
C Outside local network
D Only FTP server
Devices send traffic to the default gateway when the target IP is outside their subnet. The gateway router forwards packets to other networks, including the internet.
A subnet mask helps determine
A Local vs remote
B Browser cookie size
C Email server port
D VPN tunnel key
The subnet mask shows which part of an IP address is the network. Devices use it to decide if a destination is on the same LAN or must be sent to the default gateway.
FTP is mainly used for
A Web browsing
B File transfer
C IP assignment
D Name resolution
FTP transfers files between a client and server. It supports upload and download, but classic FTP is not encrypted, so secure alternatives like SFTP or FTPS are often preferred.
FTP control connection uses
A Port 21
B Port 25
C Port 80
D Port 443
FTP typically uses port 21 for control commands like login and directory operations. Data transfers use separate connections, which is why FTP can be tricky through firewalls.
SMTP is used to
A Receive email
B Browse websites
C Send email
D Assign IPs
SMTP sends outgoing email from clients to mail servers and between mail servers. Receiving and syncing email is handled by POP3 or IMAP rather than SMTP.
POP3 is mainly used to
A Download email
B Send email
C Encrypt web traffic
D Assign DNS records
POP3 retrieves email from a server to an email client, usually storing messages locally. It is simple and common, but less ideal for users accessing mail from many devices.
IMAP is mainly used to
A Upload web pages
B Assign IP pools
C Trace network path
D Sync email
IMAP keeps messages on the server and synchronizes them across devices. It supports folders and states like read/unread, making it ideal for multi-device email use.
Ping command is used to
A Create domains
B Transfer files
C Check connectivity
D Encrypt traffic
Ping uses ICMP echo messages to test if a host responds and measures delay. It is a basic tool for checking network reachability and response time.
Traceroute command is used to
A Assign IP lease
B Show route hops
C Store cookies
D Send mail
Traceroute lists routers along the path to a destination. It helps diagnose where delays or failures occur by showing each hop and how long replies take.
A proxy server often helps with
A Filtering and caching
B Modulation of signals
C Assigning MAC IDs
D Increasing attenuation
A proxy sits between clients and the internet. It can filter websites, log access, and cache content to speed repeated requests and reduce external bandwidth use.
A VPN mainly provides
A Faster DNS resolution
B Secure encrypted tunnel
C Automatic IP leasing
D TCP sequencing only
A VPN encrypts traffic between your device and a VPN server. It improves privacy on public networks and can allow secure access to private resources over the internet.
NAT is commonly used to
A Remove all headers
B Stop packet routing
C Share public IP
D Create DNS zones
NAT translates private internal IPs to a public IP for internet access. This allows many devices to use one public IPv4 address and helps conserve limited IPv4 space.
A MAC address identifies
A Network interface card
B Website domain name
C Internet speed unit
D DNS cache memory
A MAC address uniquely identifies a network interface at the Data Link layer. It is used for local LAN communication, while IP addresses are used for routing across networks.
An ISP mainly provides
A DNS record writing
B FTP password storage
C TCP congestion control
D Internet connectivity
An ISP connects users to the internet through fiber, cable, DSL, or mobile networks. Many ISPs also provide DNS servers, modems/routers, and basic network support.
Web hosting is best described as
A Encrypting web traffic
B Assigning IP leases
C Storing site on server
D Routing DNS packets
Web hosting stores website files on servers connected to the internet. It provides storage, bandwidth, and server software so the website can be accessed by users anytime.
VoIP means
A Voice over IP
B Video over IP
C Files over IP
D DNS over IP
VoIP sends voice as IP packets over networks instead of traditional circuits. It enables internet calling but needs stable low-latency connectivity to maintain clear call quality.
Data packets are used so networks can
A Remove all noise
B Route efficiently
C Avoid protocols
D Stop attenuation
Packet switching splits data into packets that can be routed independently. This improves resource sharing and network efficiency, and the receiver reassembles packets into the original message.
A well-known port is typically in range
A 1024 to 2000
B 2000 to 4000
C 0 to 1023
D 4000 to 6000
Well-known ports are reserved for common services, like 80 for HTTP and 25 for SMTP. Many systems require special privileges to run services on these lower-numbered ports.
A protocol suite refers to
A Group of protocols
B Type of modem
C Cable connector type
D Single server address
A protocol suite is a collection of protocols designed to work together, such as TCP/IP. It includes rules for addressing, routing, transport, and application services like web and email.