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Computer Science Exam Questions with Answers Complete Practice
Solutions
1. You have a laptop with a dead hard drive. You want to replace it with a newer SSD but have a few
concerns. What disadvantages do SSDs have versus HDDs? (Choose two.)
A) They produce more heat.
B) They are more expensive.
C) They are more susceptible to damage.
D) They cost more per gigabyte.: B, D. SSDs have many advantages over HDDs, including
producing less heat and being less susceptible to damage from shock or overheating. However, they are more expensive per byte.
2. Your friend is an artist and they have recently purchased a new convertible laptop. It can be
used as a regular laptop or folded into a tablet computer. You've recommended they purchase a touch pen to use with their new com- puter. Which of the following is not an advantage of a touch pen?
A) They don't leave greasy fingerprints on your screen.
B) There are never compatibility issues.
C) They can make more precise lines than fingers can.
D) You can use them in cold weather and have gloves on your hands.: B. There are many benefits
to using a touch pen (stylus) with your touchscreen computer. For artists especially, they can be more precise in their work than is possible with fingers. They're more sanitary than fingers and don't leave behind the oils that your skin would on the screen. They're easier to create handwritten notes than using your finger is. The only downside is that they are not all
2 / compatible with every touch screen, so you need to know what kind of touchscreen you have to ensure that your touch pen is compatible with it. Most touchscreens are capacitive, which means the touch pen needs to be constructed so that it will interrupt an electrostatic field. Resistive screens only register pressure. Their advantage is that almost any material can be used to make a touch pen and resistive screens are better for uses such as making lines darker in a drawing program. There are also Bluetooth touch pens, which use a wireless signal to communicate contact with the screen.
3. In a tablet computer with an LCD, which component is responsible for
providing the right kind of energy to light the display?
A) Inverter
B) LCD
C) Backlight
D) Screen: A. Fluorescent lighting, and liquid crystal display (LCD) backlights in particular,
require fairly high-voltage, high-frequency energy. The component that provides the right kind of energy is the inverter. The inverter is a small circuit board installed behind the LCD panel that takes DC current and inverts it to AC for the backlight. An inverter is not needed in a display that uses LED backlighting.
4. A friend just purchased a touch pen that uses Bluetooth connectivity. They aren't very tech
savvy so you have offered to set it up for them. What step of the Bluetooth connection process will you do after the laptop has found the touch pen for pairing?
A) Enable pairing.
B) Test connectivity.
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B) UDP
C) Connectionless
D) Connection-oriented: A, D. Protocols are either connection-oriented, meaning they will
guarantee delivery, or connectionless, meaning they will not guarantee delivery. Connectionless protocols are used for activities such as streaming, where a missed packet here and there is less important than continuing to send the information. Connection-oriented protocols are used when it is important that each packet arrive. Some of the connection-oriented protocols are TCP, HTTPS, and SSH, whereas UDP, DHCP, and TFTP are examples of connectionless protocols.
7. Which two port numbers need to be opened to enable communications for FTP (File Transfer
Protocol)? A) 20/ B) 21/ C) 22/ D) 23/25: A. File Transfer Protocol (FTP) uses ports 20 and 21. Port 22 is used by Secure Shell (SSH), port 23 is/was used by Telnet, and port 25 is used by Simple Mail Transfer Protocol (SMTP).
8. Which Internet appliance stands between a PC and the Internet and can include stateful
packet inspection (packet filtering), and act as a gateway, translating traffic between networks or protocols? (Choose two.)
A) Spam gateway
B) Unified threat management (UTM)
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C) Load balancers
D) Proxy servers: B, D. A unified threat management (UTM) appliance is a single device on your
network that provides multiple security functions. It is usually placed between the outside world and the LAN, so it can function as a gateway as well as a security appliance.
9. In IPv6, which of the following identifies the multicast range? A) ::
B) 2001;dba:45c:1::5/ C) FE80::abc:1:2/ D) FF00::/8: D. The FF00::/8 range in IPv6 is for multicasts. Remember that IPv6 does not use broadcasts. The closest IPv6 gets is the use of multicast addresses. ::1 is the loopback address for IPv6. IP addresses that begin with 2001 are in the global unicast range, meaning that they are routable on the Internet, and the first 64 bits identify the network. Any number that starts with FE80 is nonroutable and is called a link-local address.
10. Several Bluetooth devices are connected in an ad hoc (without a hub, switch, or WAP) network.
Which acronym best describes this type of network?
A) LAN
B) WAN
C) PAN
D) MAN: C. A personal area network (PAN) is a small-scale network designed around one
person within a limited boundary area. The term generally refers to networks that use Bluetooth technology. A local area network (LAN) connects together devices in a small area such as a house or business or floor of an office building. A wide area network (WAN) covers a very large geographic area, traversing many roads
7 / printer; if you buy the least expensive paper and it's the wrong weight or coating for the printer, debris in the paper path such as dust and pieces of paper, paper with wrinkles or bent corners, too much humidity causing sheets to stick together, and worn paper feed rollers. Ink cartridges are used in inkjet printers, not laser printers, and printheads are found in impact and thermal printers, not laser printers.
13. About four computer users in the HR area of the building are complaining that their Wi-Fi
connection is very slow. You use your Wi-Fi analyzer and find out that they are on the same channel as your neighbors in the office next door. What can you do?
A) Set the radio signal to maximum.
B) Change the channel that the WAP uses.
C) Add another wireless access point.
D) Check the cable from the WAP to the router.: B. The best option to try first is changing the
channel that the wireless access point (WAP) uses to connect. The intermittent connections could be caused by interference with the neighboring Wi-Fi. Turning up the power on your WAP would only make the crossover greater between your Wi-Fi and the neighbor's Wi-Fi. Adding another WAP might help if the problem was too many users, but with only four users in that area, it's not that. You could check the cable from the WAP to the router if changing the channel doesn't resolve the issue.
14. You're reading the documentation for a desktop motherboard and it says it uses 240 pin
DIMMs. What type of DIMM does it use?
A) DDR
B) DDR
C) DDR
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D) SODIMM: A. DDR3 DIMM's have 240 pins, DDR4 and DDR5 both have 288 pins, and SODIMM
is not a type of desktop RAM; it is used in laptops.
15. You are investigating computer specifications for a new desktop worksta- tion. If the
specifications include 256 KB of L2 cache, approximately how much L1 cache would it be reasonable to expect the computer to have?
A) 64 KB
B) 256 KB
C) 512 KB
D) 12 MB: A. L1 cache is generally the smallest and fastest cache. Therefore, it's reasonable
to expect that the computer will have less L1 cache than L2.
16. A user reports that their smartphone will not make any sounds. They have turned the phone off
and back on, and the problem is still there. You check the settings, and the phone is not on silent mode and the volume is set to maximum. What can you do to fix this problem?
A) Reset the phone to factory specifications.
B) Replace the speakers.
C) Replace the sound card.
D) Replace the phone.: D. If the device does not produce sound, first make sure that it's not set
to silent operation. Most mobile devices will have a switch on the side that sets them to silent or vibrate mode, which will mute the device and keep it from making noises. Also check settings for volume as well as possible redirection of sound, such as an active Bluetooth pairing. If the speakers have failed on a mobile device, it's time for a new device.
17. A laser printer you are working on is producing images that have vertical black streaks running
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19. You have installed an 802.11ac Wi-Fi network. The network has three over- lapping wireless
access points. What channel width should the access points be set to in order to avoid communications problems while providing the best bandwidth?
A) 20 MHz.
B) 40 MHz.
C) 80 MHz.
D) It doesn't matter in 802.11ac.: B. 802.11ac is in the 5 GHz band, and can be 20, 40, or 80
MHz wide. With the 80 MHz channel width, there are effectively two channels, channel 36- and channel 149-161. Since you have three access points, you should use the 40 MHz channel width, which provides four possible channels: 36-40, 44-48, 149-153, and 157-161. The 20 MHz channel width provides nine channels, but you don't need that many, and the narrower channel width would decrease the performance per client. The 20 MHz channels are 36, 40, 44, 48, 149, 153, 157, 161, and 165.
20. A user complains that their desktop computer randomly reboots. No error messages are
displayed before it happens, and there is not a specific program that triggers the reboot. Which of the following components is most likely to be causing this problem?
A) RAM
B) Storage drive
C) BIOS/UEFI
D) Network adapter: A. Memory problems can cause system lockups, unexpected shutdowns or
reboots, or errors such as blue or black screen of death (BSOD) in Windows or the rotating pinwheel in macOS. CPUs problems can also cause intermittent
11 rebooting.
21. A user calls the help desk to report that their display is black. It was working yesterday, but
when the desktop computer was booted this morning, nothing showed on the display. They did hear a beep like normal when the computer booted up. What is the first thing you should do?
A) Reseat the plug on the video card.
B) Replace the video card.
C) Ask the user to press the display's power button.
D) Refresh the operating system.: C. When troubleshooting, always start with the simple things
first. It would not be the first time that a display had been inadvertently turned off. If that doesn't resolve it, check the cabling to ensure that nothing is loose, and check any settings on the display to ensure that the brightness isn't turned all the way down and that the display is using the correct input if it has more than one.
22. In your company's lobby, there is a desktop computer with an LCD that plays a continuous loop
of a welcome video. The display is enclosed in a cabinet. Recently, the display will shut itself down near the end of the day for no apparent reason. What is likely causing this problem?
A) Backlight failure
B) Incorrect video resolution
C) Display card failure
D) Display overheating: D. Displays may have their own internal power supply, and they all have
internal circuitry, which means they can overheat. Make sure the air vents on the back of the display are dust- and debris-free. In this case, removing the display from the cabinet might help. If the problem persists, it's best to replace the display.
23. One of your network users develops software for multiple operating sys- tems. They have
13 a coaxial cable: they degrade the signal and limit the distance the signal will travel. Use them judiciously.
26. A desktop computer will not retain the system time or date. The user always needs to reset them
after the system is powered off. What should you do to fix the problem?
A) Flash the BIOS/UEFI.
B) Replace the BIOS/UEFI chips.
C) Replace the CMOS battery.
D) Use the jumper on the motherboard to reset the BIOS/UEFI to factory settings.: C. If a computer
is a few years old, the BIOS/UEFI may fail to retain your computer's settings, such as time and date and hard drive configuration. The BIOS/UEFI uses a small battery (much like a watch battery) on the motherboard to help it retain settings when the system power is off. If this battery fails, the BIOS/UEFI won't retain its settings. Simply replace the battery with the same type to solve the problem. There is usually a number printed on top of the battery so you know which one to get.
27. A new technician trainee just turned a computer on and it beeped once. They had heard about
motherboard beep codes and ask you what that single beep means. What will you tell them?
A) Bad RAM
B) CPU issue
C) Video isn't working
D) POST completed successfully: D. When the power-on self-test (POST) com- pletes
successfully, most motherboards will emit a single beep to let you know.
28. A user has turned in a tablet computer that has a swollen battery. What should you do to
resolve the problem?
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A) Turn the tablet off, let it cool down, and then return it to the user.
B) Order a new tablet for the user, drain the excess electrolyte from the battery, and then dispose of
the defective one in the trash.
C) Order a new tablet for the user and take the defective one to a recycling center.
D) Order a new tablet for the user and throw the defective one in the trash.: C. If you have a swollen
battery, turn the device off immediately and make sure that it's not plugged into a charger. It may be possible to remove the battery, but swollen batteries are more prone to explosions than normal ones because the casing is already compromised, and most batteries in small devices are not user replaceable. The best course of action is to purchase a new device. Take the battery or device to a proper recycling center to dispose of it. Never just throw it in the trash because it can explode and harm sanitation workers as well as cause significant damage to the environment.
29. You are troubleshooting a laptop computer that will not boot properly. When you power it on,
there is nothing on the display, and you hear beeps in a pattern of 1-3-3. What two things could you use to troubleshoot the problem? (Choose two.)
A) Manufacturer's website
B) PCIe POST card
C) USB POST card
D) BOOT tester: A, C. The beeps are a BIOS beep code produced because the power-on self-test
(POST) routine has found an error. The manufacturer's website will likely tell you what the beep code means, and you can also troubleshoot using a USB POST card. Laptops do not have PCIe slots, and there is no specific tool called a BOOT tester.
30. Your motherboard supports up-plugging for PCIe adapter cards. Which of the following
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D) SDLC: B. Currently there are three form factors for SD cards; they are SD, MiniSD, and
MicroSD. The cards also come in different capacities and filesystems as follows: SD: 2 GB or less, FAT12 or FAT SDHC: 2 GB to 32 GB, FAT32 SDXC: 32 GB to 2 TB, exFAT SDUC: 2 TB to 128 TB, exFAT
33. A user reports that when they press the L key on their laptop keyboard, the L character repeats
across the screen and doesn't stop until the L key is pressed several more times. When you look at the laptop, it does not appear that the key is physically sticking. What should you do next?
A) Replace the keyboard.
B) Replace the L key.
C) Clean under the key with compressed air.
D) Reboot the laptop.: D. If a key on the laptop keyboard is stuck, you need to determine
whether the contact is having problems or whether the key itself is stuck.
17 If the key is not physically stuck but the laptop thinks it is, rebooting generally solves the problem.
34. You're working on a stormy night and the power in your house goes out, but your cellular
service (smartphone) is working. You have a report on your laptop that absolutely must be submitted tonight, and luckily your laptop is fully charged. What can you to do submit your report?
A) Connect your laptop to your car's antenna to send via Wi-Fi.
B) Use your smartphone's hotspot feature.
C) Go out in the storm and drive to the nearest place with power that has public Wi-Fi.
D) Call and let them know that the report won't be submitted because your power is out.: B. The
hotspot feature available on virtually all smartphones will enable you to connect other devices to the Internet via the cellular tower system. Typically you turn the hotspot feature on in the phone's settings. It will display a wireless password and allow you to connect wirelessly via Wi-Fi, Bluetooth, or connect physically via USB by connecting a cable between your laptop and the phone. The downside of doing this is that it eats up data quickly and could be expensive if you don't have unlimited data on your cellular plan.
35. You have determined that you need to replace the Wi-Fi antenna in your laptop. Where will you
most likely find it?
A) In the housing with the display
B) Under the keyboard
C) Under a removable panel on the back/bottom of the laptop
D) Plugged into a USB port: A. Most laptop antennas connect to the main board and have wires
that run up the sides of the display. Occasionally you may find one on the mainboard. Modern laptops typically don't have removable areas on the bottom/back
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A) Hub
B) Bridge
C) Managed switch
D) Unmanaged switch: C. To segregate a local area network (LAN) into two virtual LANs (VLANs),
you would need a managed switch. Managed switches contain software that allows for port configuration, diagnostics, and monitoring situations such as port flapping. An unmanaged switch is simply a connectivity device. It can't be used to segregate ports into separate VLANs. A bridge is used to aggregate two or more networks into one. A hub is simply a connectivity device that is a single collision domain, whereas each port on a switch (managed or not) is its own collision domain. Hubs are seldom found on networks now, but they are often used to provide multiple ports for a single connection on a computer such as a USB port. Note that some routers have the ability to create a VLAN by using different IP address ranges, but more often a switch is used.
39. On an IPv6 network, you want to send a single message to a group of
computers at the same time. What type of address class do you need to use?
A) Multicast
B) Anycast
C) Unicast
D) Broadcast: A. There are three types of addresses in IPv6: unicast, anycast, and multicast. A
unicast address identifies a single node on the network. An anycast address refers to one that has been assigned to multiple nodes. A multicast address is one used by multiple hosts. An anycast message will go to one of the hosts on the list. A multicast message will go to all of the addresses on the list. IPv6 does not use broadcasts.
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40. Which of the following IP addresses is not routable on the Internet? A) 192.169.1.
B) 192.168.1.
C) 168.192.1.
D) 169.192.1.1: B. Private IP addresses are not routable on the Internet. The following are the IPv4 private address ranges and nonroutable numbers: 10.0.0.0 to 10.255.255.255/8 (Class A) 172.16.0.0/16 to 172.31.255.255/12 (Class B) 192.168.0.0 to 192.168.255.255/16 (Class C) 169.254.0.0 to 169.254.255.255 (APIPA) 127.0.0.1 (Loopback address)
41. When setting up your network, you configured your clients to obtain IP addressing information
automatically from a DHCP server. You set the group of numbers that it can assign from 192.168.100.11 to 192.168.100.211. What is this group of assignable numbers called?
A) APIPA
B) Leases
C) Scope
D) Reservations: C. The range of numbers that can be assigned by a Dynamic Host Configuration
Protocol (DHCP) server to client computers is called the scope. Each of those numbers can be leased to the client for a period of time that you choose in the server settings. Reservations are numbers that you set aside for specific devices on the network whose IP address you don't want to change, like a server or IP printer. Automatic private IP addressing (APIPA) addresses are self- assigned by a computer that is set for dynamic IP addressing but that is unable to reach a DHCP server.
42. You're considering setting up a WISP. What is an advantage of using an unlicensed frequency
