CompTIA A+ Core 1 Practice Test

样题与解析

以下是本题库中的部分真题与完整解析。完整题库请用上方的刷题工具。

1. 1. Hardware

   Which memory technology is most commonly used as the main system RAM in a modern desktop computer?

   • a.GDDR video memory
   • b.DDR SDRAM DIMMs
   • c.NAND flash chips
   • d.EEPROM

   答案: b

   解析: Modern desktops use DDR SDRAM installed as DIMM modules for main system memory. NAND flash is used for SSDs, GDDR is dedicated video memory on graphics cards, and EEPROM stores small amounts of firmware data.

2. 2. Hardware

   How many drives are minimally required to build a RAID 5 array?

   • a.Four
   • b.One
   • c.Three
   • d.Two

   答案: c

   解析: RAID 5 distributes parity across all members and needs a minimum of three drives. It can survive the loss of a single drive by rebuilding from parity information.

3. 3. Hardware

   Which component temporarily stores data the CPU is actively using and loses its contents when powered off?

   • a.Optical disc
   • b.BIOS ROM
   • c.Hard drive
   • d.System RAM

   答案: d

   解析: System RAM is volatile memory that holds active program data and is cleared when power is removed. Hard drives and optical discs are non-volatile storage, and BIOS ROM retains firmware.

4. 4. Networking

   A client shows an IP address in the 169.254.x.x range. What does this indicate?

   • a.A static public IP
   • b.A successful DHCP lease
   • c.An IPv6 link-local address
   • d.APIPA — the client failed to reach a DHCP server

   答案: d

   解析: An address in 169.254.0.0/16 is APIPA, which a Windows host self-assigns when no DHCP server responds. It signals a DHCP problem rather than a normal lease.

5. 5. Networking

   Which connector terminates a twisted-pair Ethernet cable?

   • a.SC
   • b.RJ11
   • c.BNC
   • d.RJ45

   答案: d

   解析: Ethernet twisted-pair cables use 8-position RJ45 connectors. RJ11 is for telephone lines, BNC is coax, and SC is a fiber-optic connector.

6. 6. Mobile Devices

   Which component in a laptop allows it to connect to wireless networks and is often a replaceable M.2 card?

   • a.CMOS battery
   • b.Wi-Fi/WLAN card
   • c.Northbridge
   • d.Optical drive

   答案: b

   解析: The WLAN (Wi-Fi) card, frequently an M.2 module, provides wireless connectivity and can be serviced or upgraded. The CMOS battery, chipset, and optical drive serve different roles.

7. 7. Virtualization & Cloud

   In cloud computing, what does IaaS provide?

   • a.Only a development platform
   • b.Physical office space
   • c.Virtualized compute, storage, and networking infrastructure
   • d.Finished applications only

   答案: c

   解析: Infrastructure as a Service delivers virtual machines, storage, and networking that customers manage themselves. SaaS delivers finished apps and PaaS provides a development platform.

8. 8. Hardware & Network Troubleshooting

   What is the correct first step in the CompTIA troubleshooting methodology?

   • a.Implement the fix immediately
   • b.Identify the problem
   • c.Reboot everything
   • d.Document the outcome

   答案: b

   解析: The methodology begins with identifying the problem by gathering information and questioning the user. Establishing a theory, testing, fixing, and documenting come later in the sequence.

9. 9. Hardware & Network Troubleshooting

   A system randomly reboots under heavy load. Which cause should be investigated?

   • a.Overheating or inadequate/failing power supply
   • b.Keyboard layout
   • c.Browser cache
   • d.Wallpaper resolution

   答案: a

   解析: Random reboots under load commonly result from overheating (dust, failing fans, dried thermal paste) or a power supply that cannot sustain the load. Cosmetic software settings do not cause reboots.

10. 10. Hardware & Network Troubleshooting

    A network cable run seems dead. Which tool verifies the wiring is terminated correctly end to end?

    • a.Thermal camera
    • b.Antistatic strap
    • c.Multimeter
    • d.Cable tester

    答案: d

    解析: A cable tester checks pin-by-pin continuity and correct termination of a network cable. A multimeter measures electrical values but not Ethernet pinout mapping directly, and the others are unrelated.