CompTIA A+ Certification (2026-style) practice
questions with answers and detailed rationales
1. What is the primary purpose of RAM in a computer?
Answer: To temporarily store data for active processes
Rationale: RAM provides fast, volatile memory for running applications.
2. Which device connects multiple networks together?
Answer: Router
Rationale: A router directs traffic between different networks using IP addresses.
3. What port number does HTTPS use?
Answer: 443
Rationale: HTTPS uses port 443 for secure web communication.
4. Which component is responsible for executing instructions?
Answer: CPU
Rationale: The processor performs calculations and executes program instructions.
5. What does BIOS stand for?
Answer: Basic Input Output System
Rationale: BIOS initializes hardware during boot-up.
6. Which storage device is fastest?
Answer: NVMe SSD
Rationale: NVMe uses PCIe lanes for high-speed data transfer.
7. What type of malware encrypts files and demands payment?
Answer: Ransomware
Rationale: It locks data and demands ransom for decryption.
8. What is DHCP used for?
Answer: Automatically assigning IP addresses
Rationale: DHCP eliminates manual IP configuration.
9. Which cable is commonly used for Ethernet networking?
, Answer: RJ-45
Rationale: RJ-45 connectors are standard for Ethernet LAN connections.
10. What is the function of a firewall?
Answer: To block unauthorized network access
Rationale: Firewalls filter incoming and outgoing traffic based on rules.
11. Which OS is open-source?
Answer: Linux
Rationale: Linux source code is freely available and modifiable.
12. What tool is used to test cable continuity?
Answer: Cable tester
Rationale: It verifies proper wiring and signal flow.
13. What is phishing?
Answer: Fraudulent attempt to steal sensitive information
Rationale: Attackers impersonate trusted sources.
14. What is the function of an IP address?
Answer: Identifies a device on a network
Rationale: IP addresses allow network communication.
15. Which memory is non-volatile?
Answer: ROM
Rationale: ROM retains data even when power is off.
16. What is virtualization?
Answer: Running multiple OS on one physical machine
Rationale: Virtual machines share hardware resources.
17. Which protocol is used for secure remote access?
Answer: SSH
Rationale: SSH encrypts remote login sessions.
18. What does SSD stand for?
Answer: Solid State Drive
questions with answers and detailed rationales
1. What is the primary purpose of RAM in a computer?
Answer: To temporarily store data for active processes
Rationale: RAM provides fast, volatile memory for running applications.
2. Which device connects multiple networks together?
Answer: Router
Rationale: A router directs traffic between different networks using IP addresses.
3. What port number does HTTPS use?
Answer: 443
Rationale: HTTPS uses port 443 for secure web communication.
4. Which component is responsible for executing instructions?
Answer: CPU
Rationale: The processor performs calculations and executes program instructions.
5. What does BIOS stand for?
Answer: Basic Input Output System
Rationale: BIOS initializes hardware during boot-up.
6. Which storage device is fastest?
Answer: NVMe SSD
Rationale: NVMe uses PCIe lanes for high-speed data transfer.
7. What type of malware encrypts files and demands payment?
Answer: Ransomware
Rationale: It locks data and demands ransom for decryption.
8. What is DHCP used for?
Answer: Automatically assigning IP addresses
Rationale: DHCP eliminates manual IP configuration.
9. Which cable is commonly used for Ethernet networking?
, Answer: RJ-45
Rationale: RJ-45 connectors are standard for Ethernet LAN connections.
10. What is the function of a firewall?
Answer: To block unauthorized network access
Rationale: Firewalls filter incoming and outgoing traffic based on rules.
11. Which OS is open-source?
Answer: Linux
Rationale: Linux source code is freely available and modifiable.
12. What tool is used to test cable continuity?
Answer: Cable tester
Rationale: It verifies proper wiring and signal flow.
13. What is phishing?
Answer: Fraudulent attempt to steal sensitive information
Rationale: Attackers impersonate trusted sources.
14. What is the function of an IP address?
Answer: Identifies a device on a network
Rationale: IP addresses allow network communication.
15. Which memory is non-volatile?
Answer: ROM
Rationale: ROM retains data even when power is off.
16. What is virtualization?
Answer: Running multiple OS on one physical machine
Rationale: Virtual machines share hardware resources.
17. Which protocol is used for secure remote access?
Answer: SSH
Rationale: SSH encrypts remote login sessions.
18. What does SSD stand for?
Answer: Solid State Drive
