About this quiz
50 questions covering every section of the note: LAN, WAN, Topology, Devices, OSI Model, IP Address and Protocols.
This Lok Sewa practice set has 50 multiple-choice questions (Subject: Computer Knowledge · For: Kharidar, Nayab Subba, Section Officer · Level: Easy). Take the quiz above first; after that, use the study list below to revise every question with its correct answer and a short explanation.
Study list: all 50 questions with answers and explanations
A network that covers one office building is a:
- A) WAN
- B) MAN
- C) LAN ✔
- D) PAN
Why: A network within one building or office is a LAN (Local Area Network).
The largest example of a WAN is:
- A) Intranet
- B) The internet ✔
- C) Bluetooth
- D) A school LAN
Why: The internet is the largest example of a WAN (Wide Area Network).
Connecting a phone to wireless earphones with Bluetooth forms a:
- A) PAN ✔
- B) LAN
- C) MAN
- D) WAN
Why: Bluetooth devices around one person form a PAN (Personal Area Network).
In which topology are all devices connected to a central hub or switch?
- A) Bus
- B) Ring
- C) Star ✔
- D) Mesh
Why: In a star topology every device connects to a central hub or switch.
Which topology is the most reliable but also the most expensive?
- A) Bus
- B) Star
- C) Ring
- D) Mesh ✔
Why: In a mesh every device is linked to every other, so there are many paths.
How many links are needed to connect 5 computers in a full mesh?
- A) 5
- B) 10 ✔
- C) 20
- D) 25
Why: A full mesh of n computers needs n(n − 1) ÷ 2 links: 5 × 4 ÷ 2 = 10.
Which transmission medium carries data in the form of light?
- A) Coaxial cable
- B) Twisted pair cable
- C) Optical fibre ✔
- D) Radio waves
Why: Optical fibre carries data as pulses of light.
Which connector is used with twisted pair cable in a LAN?
- A) RJ-11
- B) RJ-45 ✔
- C) BNC
- D) HDMI
Why: RJ-45 connectors are used with twisted pair (Ethernet) cable. RJ-11 is for telephone lines.
Which device connects two different networks and chooses the best path for data?
- A) Hub
- B) Switch
- C) Router ✔
- D) Repeater
Why: A router connects different networks and chooses the best path for data.
Which device sends data only to the correct computer using the MAC address?
- A) Hub
- B) Switch ✔
- C) Repeater
- D) Modem
Why: A switch learns MAC addresses and forwards data only to the right port.
The word modem is short for:
- A) Modern demand
- B) Modulator-demodulator ✔
- C) Mode emitter
- D) Mobile data modem
Why: Modem is short for modulator-demodulator.
How many layers are there in the OSI model?
- A) 4
- B) 5
- C) 7 ✔
- D) 8
Why: The OSI model has 7 layers.
Which is the lowest (first) layer of the OSI model?
- A) Application
- B) Physical ✔
- C) Network
- D) Transport
Why: Layer 1 is the Physical layer; layer 7 is the Application layer.
IP addressing and routing happen in which OSI layer?
- A) Data Link
- B) Network ✔
- C) Session
- D) Presentation
Why: IP addressing and routing happen at the Network layer (layer 3).
An IPv4 address is made of how many bits?
- A) 16
- B) 32 ✔
- C) 64
- D) 128
Why: An IPv4 address has 32 bits, written as four numbers such as 192.168.1.1.
A MAC address is how many bits long?
- A) 32
- B) 48 ✔
- C) 64
- D) 128
Why: A MAC address is 48 bits, written as six pairs of hexadecimal digits.
Which system changes a domain name such as loksewapathsala.com into an IP address?
- A) DHCP
- B) DNS ✔
- C) FTP
- D) SMTP
Why: DNS (Domain Name System) changes a domain name into an IP address.
Which protocol is used to send email?
- A) POP3
- B) IMAP
- C) SMTP ✔
- D) HTTP
Why: SMTP is used to send email. POP3 and IMAP are used to receive it.
A walkie-talkie uses which transmission mode?
- A) Simplex
- B) Half duplex ✔
- C) Full duplex
- D) Multiplex
Why: Both sides can talk, but only one at a time, which is half duplex.
Which protocol gives IP addresses to devices automatically?
- A) DNS
- B) DHCP ✔
- C) HTTP
- D) FTP
Why: DHCP gives IP addresses to devices automatically.
LAN stands for:
- A) Large Area Network
- B) Long Access Network
- C) Local Area Network ✔
- D) Local Access Node
Why: LAN stands for Local Area Network.
A network covering a city is a:
- A) LAN
- B) PAN
- C) WAN
- D) MAN ✔
Why: A network covering a city is a MAN (Metropolitan Area Network).
The Internet is the largest example of a:
- A) WAN ✔
- B) LAN
- C) PAN
- D) MAN
Why: The internet is the largest WAN.
A network around one person, like Bluetooth devices, is a:
- A) LAN
- B) PAN ✔
- C) MAN
- D) WAN
Why: A network around one person is a PAN.
A topology where all devices connect to one central device is:
- A) Bus
- B) Ring
- C) Star ✔
- D) Mesh
Why: In a star topology all devices connect to one central device, such as a switch.
A topology where all devices share one main cable is:
- A) Star
- B) Ring
- C) Tree
- D) Bus ✔
Why: In a bus topology all devices share one main cable.
A topology where each device connects to every other device is:
- A) Mesh ✔
- B) Star
- C) Bus
- D) Ring
Why: In a mesh topology each device connects to every other device.
A topology where data travels in a closed loop is:
- A) Bus
- B) Ring ✔
- C) Star
- D) Tree
Why: In a ring topology data travels in a closed loop.
The OSI model has how many layers?
- A) 4
- B) 5
- C) 7 ✔
- D) 6
Why: The OSI model has 7 layers.
The top layer of the OSI model is the:
- A) Physical layer
- B) Network layer
- C) Session layer
- D) Application layer ✔
Why: The Application layer (layer 7) is the top layer.
The bottom layer of the OSI model is the:
- A) Physical layer ✔
- B) Data link layer
- C) Transport layer
- D) Application layer
Why: The Physical layer (layer 1) is the bottom layer.
IP addresses are handled at which OSI layer?
- A) Transport layer
- B) Network layer ✔
- C) Physical layer
- D) Session layer
Why: IP addresses are handled at the Network layer.
TCP works at which OSI layer?
- A) Network layer
- B) Application layer
- C) Transport layer ✔
- D) Physical layer
Why: TCP works at the Transport layer (layer 4).
A device that connects different networks and routes data is a:
- A) Hub
- B) Repeater
- C) Modem only
- D) Router ✔
Why: A router connects different networks and routes data.
A device that sends data only to the intended device in a LAN is a:
- A) Switch ✔
- B) Hub
- C) Repeater
- D) Modem
Why: A switch sends data only to the intended device.
A device that sends data to all ports is a:
- A) Switch
- B) Hub ✔
- C) Router
- D) Bridge
Why: A hub sends data to all its ports.
A modem converts:
- A) Text to speech
- B) AC to DC
- C) Digital signals to analog and back ✔
- D) Images to sound
Why: A modem converts digital signals to analog and back.
An IPv4 address has how many bits?
- A) 64
- B) 128
- C) 16
- D) 32 ✔
Why: An IPv4 address has 32 bits.
An IPv6 address has how many bits?
- A) 128 ✔
- B) 32
- C) 64
- D) 256
Why: An IPv6 address has 128 bits.
A MAC address is a:
- A) Website address
- B) Hardware address of a network card ✔
- C) Email address
- D) Postal code
Why: A MAC address is the hardware address of a network card.
DNS converts:
- A) IP into MAC
- B) Text into images
- C) Domain names into IP addresses ✔
- D) Files into folders
Why: DNS converts domain names into IP addresses.
The protocol for transferring web pages is:
- A) FTP
- B) SMTP
- C) POP3
- D) HTTP ✔
Why: HTTP transfers web pages.
The protocol used for sending email is:
- A) SMTP ✔
- B) HTTP
- C) FTP
- D) DNS
Why: SMTP sends email.
The protocol for transferring files is:
- A) SMTP
- B) FTP ✔
- C) HTTP
- D) DHCP
Why: FTP transfers files.
DHCP automatically assigns:
- A) Passwords
- B) Domain names
- C) IP addresses ✔
- D) Printers
Why: DHCP assigns IP addresses automatically.
Wi-Fi is a:
- A) Type of cable
- B) Virus
- C) Printer
- D) Wireless LAN technology ✔
Why: Wi-Fi is a wireless LAN technology.
Fiber optic cable transmits data using:
- A) Light ✔
- B) Electricity only
- C) Sound
- D) Radio waves only
Why: Fibre optic cable transmits data using light.
Twisted pair cables commonly used in LANs are:
- A) Coaxial only
- B) UTP (Cat 5e/Cat 6) ✔
- C) Fiber only
- D) HDMI
Why: LANs commonly use UTP twisted pair cables such as Cat 5e and Cat 6.
Bandwidth is the:
- A) Size of a monitor
- B) Speed of a printer
- C) Data transfer capacity of a network ✔
- D) Storage of a disk
Why: Bandwidth is a network's data transfer capacity.
A security system that filters network traffic is a:
- A) Router only
- B) Hub
- C) Modem
- D) Firewall ✔
Why: A firewall filters network traffic to block threats.