FC0-U71 Hard Questions — 25 Difficult Questions

Question 1

A developer is writing pseudocode for a program that calculates the average of a list of numbers. Which THREE of the following are valid components that would likely appear in the pseudocode? (Select THREE.)

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Initialize sum to 0. Initializing a variable (like sum) to a starting value (0) is a fundamental step in accumulation algorithms. Without this initialization, the sum would contain an undefined or garbage value, leading to incorrect results. This is a standard practice in pseudocode and real programming languages alike.

Answer

Define a class named Calculator

Answer

Execute SQL query to retrieve numbers from database

Question 2

A university database includes a table named 'Students' and a table named 'Enrollments'. The 'Enrollments' table has a foreign key column 'StudentID' that references the 'StudentID' primary key in the 'Students' table. The university policy requires that when a student withdraws (i.e., their record is deleted from the 'Students' table), all of their associated enrollment records must be automatically removed to maintain data consistency. The database administrator wants to enforce this rule at the database level. Which referential action should be applied when creating the foreign key constraint on the 'Enrollments' table?

Accepted Answer

ON DELETE CASCADE. (ON DELETE CASCADE) is correct because it automatically deletes all child rows in the 'Enrollments' table when the corresponding parent row in the 'Students' table is deleted. This enforces the university policy of removing associated enrollment records upon student withdrawal, maintaining referential integrity at the database level without manual intervention.

Answer

ON DELETE SET NULL

Answer

ON DELETE NO ACTION

Answer

ON DELETE RESTRICT

Question 3

A technician is explaining the difference between volatile and non-volatile memory to a trainee. Which TWO of the following are examples of volatile memory? (Select TWO.)

Accepted Answer

DDR4 RAM. Volatile memory loses data when power is off. RAM (including DDR4 and DDR5) and cache memory (L1/L2/L3) are volatile. ROM and SSDs are non-volatile.

Answer

ROM

Answer

BIOS firmware

Answer

SSD

Question 4

After deploying a new version of a web application, the QA team runs a set of test cases that were previously executed on the old version to ensure that existing functionality still works correctly. This testing is performed to detect any unintended side effects of the changes. What type of testing is this?

Accepted Answer

Regression testing. Regression testing verifies that new code changes do not break existing functionality.

Answer

Integration testing

Answer

Smoke testing

Answer

Acceptance testing

Question 5

A user has a desktop computer with a SATA SSD and wants to upgrade to an NVMe M.2 SSD. The motherboard has an M.2 slot. What must the user verify before purchasing the NVMe drive?

Accepted Answer

The M.2 slot supports NVMe (PCIe).. NVMe M.2 drives use the PCIe interface and require a motherboard that supports NVMe via M.2 slot with PCIe lanes.

Answer

The power supply has enough wattage.

Answer

The operating system is 64-bit.

Answer

The SATA cable is compatible.

Question 6

A help desk technician receives a call from a user who cannot connect to a network share. The user's computer shows a network icon with a red X. The technician asks the user to check the network cable connection. The user reports that the cable is securely connected. The technician then pings the default gateway from their own computer and the ping is successful. Which of the following is the NEXT step the technician should take?

Accepted Answer

Check the IP configuration on the user's computer. The user's computer shows a network icon with a red X, indicating a physical or data-link layer issue, but the cable is reported as securely connected. The technician successfully pings the default gateway from their own computer, proving the network infrastructure (router, switch, cabling) is functional. The next logical step is to check the IP configuration on the user's computer, as a missing or misconfigured IP address (e.g., APIPA 169.254.x.x due to DHCP failure) could prevent connectivity even with a good cable. This isolates the problem to the user's device rather than the network.

Answer

Replace the network cable

Answer

Restart the network share server

Answer

Disable the firewall on the user's computer

Question 7

A security analyst is explaining the difference between a threat and a vulnerability. Which statement accurately describes this difference?

Accepted Answer

A threat is a potential cause of harm, and a vulnerability is a weakness that can be exploited.. A vulnerability is a weakness, while a threat is a potential danger that exploits that weakness.

Answer

A vulnerability is a risk, and a threat is a countermeasure.

Answer

A threat is a weakness in a system, and a vulnerability is an attack that exploits it.

Answer

A vulnerability is a potential harm, and a threat is likelihood times impact.

Question 8

A network administrator is setting up a small office network with 20 computers. The network must be easy to troubleshoot and resilient to a single cable failure affecting only one device. Which topology is most appropriate?

Accepted Answer

Star. Star topology connects each device to a central switch. If one cable fails, only that device is affected, making it easy to troubleshoot. It is the most common for modern networks.

Answer

Ring

Answer

Bus

Answer

Mesh

Question 9

Which THREE are valid primitive data types in most programming languages? (Choose three.)

Accepted Answer

Character. Character (B), Boolean (C), and Integer (D) are all primitive data types because they represent single, indivisible values directly supported by the language's type system: a character holds one text symbol (e.g., char in C/Java), a Boolean holds true/false, and an integer holds a whole number. These types are typically built into the language and stored as simple values rather than as composite structures. In contrast, String (A) is generally a composite or reference type (e.g., a sequence of characters, such as java.lang.String), and Array (E) is a derived/aggregate data structure that holds multiple elements, so neither qualifies as primitive.

Answer

String

Answer

Array

Question 10

A software developer is writing a script that needs to run a set of instructions repeatedly until a condition is met. Which programming construct should be used?

Accepted Answer

While loop. A while loop is the correct construct because it repeatedly executes a block of code as long as a specified condition remains true. This is ideal for scenarios where the number of iterations is not known in advance and depends on a dynamic condition, such as waiting for a file to appear or a network response.

Answer

For loop

Answer

If-else statement

Answer

Function definition

Question 11

A server has four hard drives configured in RAID 5. One drive fails. What must the technician do to restore full redundancy?

Accepted Answer

Replace the failed drive and rebuild the array. RAID 5 uses distributed parity across all drives, allowing the array to tolerate a single drive failure without data loss. When a drive fails, the technician must replace the failed drive and then rebuild the array, during which the RAID controller reconstructs the missing data from the parity information on the remaining drives. This restores full redundancy by returning the array to a fault-tolerant state.

Answer

Replace all drives and reconfigure RAID

Answer

Simply replace the drive with a larger capacity drive

Answer

Replace the failed drive and restore from backup

Question 12

A developer is debugging a program that is producing incorrect output. Which of the following are common debugging techniques? (Choose three.)

Accepted Answer

Using a debugger. Using a debugger (A) is a core debugging technique because it lets the developer set breakpoints, step through execution line by line, inspect variables and the call stack, and observe the program's state at the exact point where output diverges from expectations. Code review (B) is also a common debugging technique: a careful reading of the source, often by a second developer, can reveal logic errors, off-by-one mistakes, incorrect conditionals, or misuse of APIs that cause incorrect output. Adding print statements (C) is a classic and widely used technique, inserting temporary logging at key points to trace variable values and control flow and thereby localize the faulty logic. Reinstalling the operating system (D) is not a debugging technique for a program producing wrong output; it is a drastic system-recovery action that would not address a logic or coding defect. Changing the program requirements (E) is not debugging either, since debugging means finding and fixing the defect in the code, not redefining what the program is supposed to do.

Answer

Reinstalling the operating system

Answer

Changing the program requirements

Question 13

Which of the following encryption methods is used to protect data in transit over a public network, such as the internet?

Accepted Answer

VPN. A VPN encrypts data traffic over public networks, providing a secure tunnel for data in transit.

Answer

Full disk encryption

Answer

File encryption

Answer

HTTPS

Question 14

A developer is creating a cloud-based application that needs to authenticate third-party services before allowing access to its API. The developer decides to use a method where each third-party service receives a unique key that must be included in each API request. This method is known as:

Accepted Answer

API key authentication. API key authentication issues a unique key to each third-party service, which is then included in every API request (typically in a header or query string) so the server can identify and authorize the caller. This matches the scenario exactly: unique keys per consumer, presented on each request. It is a lightweight, stateless credential mechanism distinct from user-session or delegated-authorization models.

Answer

Session-based authentication

Answer

Basic authentication

Answer

OAuth

Question 15

A small business has a single server running Windows Server 2019 that acts as a domain controller, file server, and DHCP server. The server has a single network interface with IP address 192.168.1.10/24. The office has 30 client computers running Windows 10. All clients obtain IP addresses automatically. The network uses a single unmanaged switch. The internet connection is provided by a cable modem with IP 192.168.1.1. The server is configured with a static IP of 192.168.1.10, and the DHCP scope is 192.168.1.100-192.168.1.200. Recently, users have reported that they cannot access the internet. The technician checks that the cable modem is online and that the server can ping the modem. The technician runs 'ipconfig /all' on a client and sees: IP: 192.168.1.101, Subnet: 255.255.255.0, Default Gateway: 192.168.1.10, DNS: 192.168.1.10. The client can ping the server (192.168.1.10) but cannot ping the modem (192.168.1.1). What is the most likely cause?

Accepted Answer

Change the DHCP scope option for the default gateway to 192.168.1.1. The DHCP scope is configured with the default gateway option set to 192.168.1.10 (the server's IP), but the actual default gateway for internet access is the cable modem at 192.168.1.1. Since clients receive their gateway via DHCP, they are sending all off-subnet traffic to the server, which is not configured to route to the internet. Changing the DHCP scope option for the default gateway to 192.168.1.1 will allow clients to route internet traffic through the modem.

Answer

Disable the Windows Firewall on the server to allow traffic

Answer

Replace the cable modem as it is not routing traffic correctly

Answer

Configure the DNS server to forward queries to 8.8.8.8

Question 16

During a sprint retrospective, the team identifies that too many bugs are being discovered late in the development cycle. They decide to introduce a practice where developers write tests for individual functions before coding the functions themselves. This approach is an example of:

Accepted Answer

Unit testing. Writing tests for individual functions before writing the functions themselves is the definition of unit testing, and doing so before coding is specifically test-driven development (TDD). Unit tests isolate the smallest testable pieces of code (functions, methods) to verify correctness. This matches the scenario's focus on individual functions and early bug detection.

Answer

User acceptance testing

Answer

Integration testing

Answer

System testing

Question 17

A developer is working on a collaborative software project and uses Git for version control. The developer creates a new feature on a separate branch. After completing the feature, what is the typical next step to integrate the changes into the main branch?

Accepted Answer

Merge the feature branch into the main branch. After completing work on a feature branch, the typical next step is to merge the feature branch into the main branch to integrate the changes. This is the standard Git workflow: create a branch, commit changes, then merge back into the mainline (often via a pull request). Merging combines the histories and brings the feature into the main branch.

Answer

Commit the changes directly to the main branch

Answer

Delete the feature branch without merging

Answer

Push the branch to the remote repository

Question 18

A company wants to protect against data loss if a single hard drive fails. They have three identical drives. Which RAID configuration provides fault tolerance while maximizing storage capacity?

Accepted Answer

RAID 5. RAID 5 uses block-level striping with distributed parity, so if one of the three drives fails, the data can be rebuilt from the remaining drives plus the parity information. With three drives, RAID 5 provides fault tolerance for a single drive failure while using only one drive's worth of capacity for parity, maximizing usable storage (2/3 of total raw capacity).

Answer

RAID 0

Answer

JBOD

Answer

RAID 1

Question 19

A small real estate office with 12 employees has been using the same network setup for five years. Employees use both company-issued laptops and personal smartphones to access email and client listings. Last week, an employee clicked a link in a phishing email, which led to a ransomware infection on the company file server. The server was encrypted, and the attackers demanded a ransom. The office had no backups; all client data and contracts were lost. The office manager wants to prevent such incidents in the future. Which of the following should be the FIRST security measure implemented, considering the root cause of the breach?

Accepted Answer

Mandate security awareness training for all employees, focusing on phishing identification. The root cause was a phishing email that tricked an employee. While technical controls like antivirus (A), next-generation firewall (B), and full-disk encryption (C) are valuable, they do not address the human factor. Security awareness training (D) educates users to recognize phishing attempts, reducing the likelihood of similar incidents. Without training, other controls can be bypassed. Option D is the most direct and effective first step.

Answer

Install antivirus software on all company laptops and personal devices

Answer

Deploy a next-generation firewall with intrusion prevention

Answer

Enable full-disk encryption on all company laptops

Question 20

A system administrator is configuring a server to provide email services for a small business. The business wants to avoid managing the underlying infrastructure. Which cloud service model best fits this need?

Accepted Answer

SaaS. SaaS delivers fully managed applications where the provider handles all underlying infrastructure, patching, and maintenance — the customer simply uses the email service. This matches the requirement to avoid managing infrastructure. Examples include Microsoft 365, Google Workspace, and Zoho Mail.

Answer

IaaS

Answer

DaaS

Answer

PaaS