Free CompTIA A+ Practice Questions

Question 1 · Core 1 · Networking

Which TCP port does Remote Desktop Protocol (RDP) use by default?

• A. 22
• B. 3389
• C. 443
• D. 8080

Answer: B. RDP uses TCP 3389 for remote graphical access to Windows. Port 22 is SSH and 443 is HTTPS.

Question 2 · Core 1 · Hardware

You need fault tolerance that survives a single drive failure while wasting the least capacity. Which RAID level fits best?

• A. RAID 0
• B. RAID 1
• C. RAID 5
• D. RAID 10

Answer: C. RAID 5 stripes data with distributed parity, surviving one drive failure with only one drive of overhead. RAID 0 has no redundancy; RAID 1 and 10 mirror, costing 50% of capacity.

Question 3 · Core 1 · Mobile Devices

Which connector is reversible and used by most modern Android phones, laptops, and peripherals?

• A. Micro-USB
• B. Lightning
• C. USB-C
• D. Mini-USB

Answer: C. USB-C is reversible and carries power, data, and (with alt modes) video. Lightning is Apple-proprietary; micro and mini-USB are older and not reversible.

Question 4 · Core 1 · Networking

What is the default subnet mask for a Class C IPv4 address?

• A. 255.0.0.0
• B. 255.255.0.0
• C. 255.255.255.0
• D. 255.255.255.255

Answer: C. Class C uses a /24 mask, 255.255.255.0, leaving 254 usable host addresses. Class A is 255.0.0.0 and Class B is 255.255.0.0.

Question 5 · Core 1 · Virtualization & Cloud

Which cloud service model provides virtual machines, storage, and networking while the customer manages the operating system and applications?

• A. SaaS
• B. PaaS
• C. IaaS
• D. DaaS

Answer: C. Infrastructure as a Service (IaaS) gives you the virtual hardware and you manage the OS and up. PaaS adds a managed runtime; SaaS delivers the finished application.

Question 6 · Core 1 · Troubleshooting

A PC powers on with fans spinning but shows no display and emits repeating beep codes. What is the BEST first step?

• A. Replace the power supply
• B. Reseat the RAM
• C. Reinstall the operating system
• D. Replace the CPU

Answer: B. Repeating POST beep codes most often indicate a memory problem. Reseating or testing the RAM is the quickest, lowest-cost first step before replacing pricier parts.

Question 7 · Core 2 · Operating Systems

Which Windows file system supports access permissions, EFS encryption, journaling, and very large volumes?

• A. FAT32
• B. exFAT
• C. NTFS
• D. ext4

Answer: C. NTFS supports permissions, EFS, compression, journaling, and large files and volumes. FAT32 has a 4 GB file-size limit and no permissions; ext4 is a Linux file system.

Question 8 · Core 2 · Security

Following best-practice malware removal, what should you do immediately after you identify and verify malware symptoms?

• A. Educate the end user
• B. Quarantine the infected system
• C. Run a full backup
• D. Reimage the drive

Answer: B. The order is: identify and verify, quarantine, disable System Restore (Windows), remediate, schedule scans and updates, re-enable System Restore, then educate the user. Quarantine comes right after identification to stop the spread.

Question 9 · Core 2 · Operational Procedures

Which class of fire extinguisher is rated for energized electrical fires, such as a burning power supply?

• A. Class A
• B. Class B
• C. Class C
• D. Class K

Answer: C. Class C extinguishers are for energized electrical equipment. Class A is for ordinary combustibles, Class B for flammable liquids, and Class K for cooking oils.

Question 10 · Core 2 · Security

A login that requires a password plus a one-time code from an authenticator app is an example of what?

• A. Single sign-on
• B. Multifactor authentication
• C. Role-based access control
• D. Biometric authentication

Answer: B. Combining something you know (the password) with something you have (the code-generating app) is multifactor authentication (MFA). SSO is one login for many apps; RBAC grants access by role.