AZ-900 Describe cloud concepts Practice Test 6 — 15 Questions

Question 1

A company is evaluating cloud service models. They need to migrate an existing application that requires full control over the operating system and custom software installations. They do not want to manage the underlying physical hardware. Which cloud service model best fits this requirement?

Accepted Answer

Infrastructure as a Service (IaaS). Infrastructure as a Service (IaaS) provides virtualized computing resources over the internet, including virtual machines with full control over the guest operating system. This allows the company to install custom software and manage the OS while the cloud provider handles the underlying physical hardware, such as servers, storage, and networking. The requirement for full OS control and custom software installations excludes PaaS and SaaS, which abstract away the OS layer.

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Platform as a Service (PaaS)

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Software as a Service (SaaS)

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On-premises deployment

Question 2

A company is designing a multi-cloud strategy to avoid dependency on a single provider. They need the ability to move workloads between different cloud providers or back to an on-premises environment with minimal rework. Which cloud characteristic is most essential for this goal?

Accepted Answer

Portability. Portability is the cloud characteristic that enables workloads, data, and applications to be moved across different cloud providers or between cloud and on-premises environments with minimal rework. This is achieved through the use of standardized formats, APIs, and containerization technologies such as Docker and Kubernetes, which abstract underlying infrastructure dependencies. For a multi-cloud strategy aimed at avoiding vendor lock-in, portability is the essential enabler.

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Elasticity

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Scalability

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Fault tolerance

Question 3

A startup wants to migrate its application to Azure. The development team needs to be able to provision virtual machines and storage on demand without waiting for manual approval from a central IT team. Which characteristic of cloud computing directly fulfills this requirement?

Accepted Answer

On-demand self-service. B is correct because on-demand self-service allows users to provision cloud resources like virtual machines and storage automatically, without requiring human interaction or manual approval from a central IT team. This characteristic is defined by NIST SP 800-145 as the ability for a consumer to unilaterally provision computing capabilities as needed, which directly matches the startup's requirement for no-wait provisioning.

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Measured service

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Rapid elasticity

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Resource pooling

Question 4

A company runs a web application in Azure that experiences variable traffic throughout the day. During peak hours, the application becomes slow because the existing virtual machine (VM) cannot handle the increased load. The solution architect proposes adding more VMs of the same size and distributing incoming requests across all of them to balance the load. Which scaling concept does this approach represent?

Accepted Answer

Horizontal scaling. Horizontal scaling (also known as scaling out) involves adding more virtual machines of the same size to distribute incoming traffic across them. In this scenario, adding more VMs of the same size and using a load balancer to distribute requests directly matches the definition of horizontal scaling, which increases system capacity by adding more instances rather than increasing the power of a single instance.

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Vertical scaling

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Elastic scaling

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Disaster recovery

Question 5

A retail company is planning to migrate its e-commerce application to Azure. The application will run on an Azure virtual machine that the company will manage. The IT manager wants to ensure that security patches are applied promptly. According to the shared responsibility model, who is responsible for applying security updates to the guest operating system of the Azure virtual machine?

Accepted Answer

The customer, because the guest operating system is under the customer's control.. In the shared responsibility model, the customer is responsible for securing and patching the guest operating system (OS) of an Azure virtual machine because the customer retains control over the OS, applications, and data. Microsoft manages the underlying hypervisor and physical infrastructure but does not have access to the guest OS. Therefore, the customer must apply security updates to the guest OS.

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Microsoft, because they manage the hypervisor under the virtual machine.

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Both Microsoft and the customer share responsibility equally for patching the guest operating system.

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The customer, but only if they have configured Azure Policy to enforce patch compliance.

Question 6

A company runs a legacy application on-premises that cannot be migrated to the cloud due to strict data sovereignty laws requiring customer data to remain within the country's physical borders. The company wants to use Azure's advanced analytics services to gain insights from the data. They plan to keep the data on-premises but run the analytics workloads in Azure. Which cloud deployment model should they use?

Accepted Answer

Hybrid cloud. The hybrid cloud model is correct because it combines on-premises infrastructure (for data sovereignty compliance) with Azure's public cloud services (for advanced analytics). This allows the company to keep customer data within the country's physical borders while leveraging Azure's analytics workloads, such as Azure Synapse Analytics or Azure Machine Learning, without migrating the data to the cloud.

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Public cloud

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Private cloud

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Community cloud

Question 7

A manufacturing company is planning to move its on-premises infrastructure to Azure. The CFO wants to understand the financial impact. Currently, the company purchases servers and networking equipment upfront, which depreciates over three years. In Azure, they will pay only for the compute and storage resources they consume on a monthly basis. Which cloud concept best describes this shift in cost structure?

Accepted Answer

Operational expenditure (OpEx). The shift from upfront hardware purchases (capital expenditure) to paying only for consumed resources monthly is the definition of operational expenditure (OpEx). In Azure, this is enabled by the consumption-based pricing model, where you are billed for compute hours, storage GBs, and data egress rather than owning physical assets. This directly addresses the CFO's concern about financial impact by converting large upfront costs into predictable, variable monthly payments.

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Scalability

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High availability

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Resource pooling

Question 8

A company runs a nightly data processing job that requires high CPU usage for only 15 minutes. During the day, the compute resources are idle. The company wants to reduce costs by automatically starting compute resources only when the job runs and shutting them down after completion, without manual intervention. Which cloud computing characteristic directly meets this requirement?

Accepted Answer

Elasticity. Elasticity is the cloud computing characteristic that enables resources to be automatically provisioned and de-provisioned in response to workload demands. In this scenario, the nightly job requires high CPU for only 15 minutes, and elasticity allows the compute resources to scale up exactly when the job starts and scale down to zero after completion, eliminating idle costs without manual intervention.

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High availability

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Fault tolerance

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Scalability

Question 9

A company is migrating a custom-built inventory management application to the cloud. The application runs on a specific version of Windows Server and requires custom registry settings that are not supported in a platform as a service (PaaS) offering. The company wants to avoid the overhead of managing physical servers but still needs full control over the operating system and application dependencies. Which cloud service model should the company use?

Accepted Answer

Infrastructure as a Service (IaaS). The company needs full control over the operating system and custom registry settings, which are not supported in PaaS. Infrastructure as a Service (IaaS) provides virtualized computing resources (e.g., virtual machines) where the customer manages the OS, applications, and dependencies, while the cloud provider handles the physical hardware. This model allows the company to run a specific version of Windows Server with custom registry configurations without managing physical servers.

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Platform as a Service (PaaS)

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Software as a Service (SaaS)

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Function as a Service (FaaS)

Question 10

A retail company runs an e-commerce website on Azure. The website experiences highly unpredictable traffic with occasional sudden spikes (e.g., during flash sales). Outside of sales events, the website has low traffic. The company wants to automatically increase the number of virtual machines during peak demand and automatically reduce them when demand subsides, without any manual intervention. The primary goal is to handle variable demand efficiently while minimizing cost. Which cloud computing characteristic best describes this capability?

Accepted Answer

Elasticity. Elasticity is the correct answer because it specifically refers to the ability of a cloud system to automatically provision and de-provision resources (such as virtual machines) in response to real-time demand changes. In this scenario, the e-commerce website needs to scale out during flash sales and scale in during low traffic periods without manual intervention, which is the defining characteristic of elasticity. This capability directly supports the goal of handling variable demand efficiently while minimizing cost, as resources are only consumed when needed.

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High availability

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Fault tolerance

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Scalability

Question 11

A company deploys an Azure SQL Database. The company is billed based on the amount of data stored and the number of transactions per second (DTUs). At the end of each month, the company receives an invoice that itemizes the exact usage and the corresponding charges. Which of the five essential characteristics of cloud computing does this billing model primarily demonstrate?

Accepted Answer

Measured service. The billing model for Azure SQL Database, which itemizes usage based on data stored and transactions per second (DTUs), directly demonstrates the 'Measured service' characteristic. This is because cloud providers meter and charge for resource consumption (storage and DTUs) with pay-per-use billing, providing transparency for both the provider and consumer. The detailed invoice showing exact usage and charges is the hallmark of measured service, where usage is monitored, controlled, and reported.

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On-demand self-service

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Broad network access

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Resource pooling

Question 12

A company is migrating a legacy customer relationship management (CRM) application to Azure infrastructure as a service (IaaS). The application runs on Windows Server and uses a third-party database. The company's IT team will manage the application and database software. However, they want to minimize their operational overhead for tasks that Azure can handle automatically. According to the shared responsibility model, which of the following tasks is the responsibility of Microsoft?

Accepted Answer

Replacing a failed physical hard disk drive in the Azure data center.. In the shared responsibility model, Microsoft is responsible for the 'physical' aspects of the cloud, including the hardware, network, and data center infrastructure. Replacing a failed physical hard disk drive is a physical infrastructure task that falls under Microsoft's responsibility, as the customer has no access to the underlying hardware in an IaaS environment.

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Applying security updates to the CRM application code.

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Configuring firewall rules within the virtual network.

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Installing the latest Windows Server security patches on the virtual machine.

Question 13

A company has a legacy on-premises application that processes sensitive financial data. Due to regulatory requirements, certain data cannot leave the company's on-premises data center. However, the company wants to take advantage of the cloud's scalability for the application's compute-intensive batch processing jobs. The batch jobs need to access the sensitive data but must process it without the data ever being stored in the cloud. The batch jobs will be orchestrated from the cloud. Which cloud deployment model best describes this architecture?

Accepted Answer

Hybrid cloud. This architecture is a hybrid cloud because it combines on-premises infrastructure (where sensitive data resides and must remain) with public cloud resources (for compute-intensive batch processing). The batch jobs are orchestrated from the cloud but access the sensitive data on-premises without storing it in the cloud, which is a classic hybrid deployment pattern. Hybrid cloud enables workload portability and orchestration across private and public environments while meeting data residency and regulatory requirements.

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Public cloud

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Private cloud

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Multi-cloud

Question 14

A startup company is developing a new mobile application. The development team needs to quickly create test environments to validate new features. They can provision virtual machines and databases in Azure within minutes, use them for a few hours, and then delete them when done. This ability to rapidly deploy and decommission resources directly supports which cloud computing benefit?

Accepted Answer

Agility. The scenario describes the ability to rapidly provision and decommission Azure resources like virtual machines and databases in minutes, use them for a few hours, and then delete them. This directly supports cloud agility, which is the cloud computing benefit that enables organizations to quickly adapt to changing requirements by deploying and releasing resources on demand. Agility is about speed and flexibility in resource management, not just scaling or metering.

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Scalability

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Elasticity

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Measured service

Question 15

A company is evaluating moving its on-premises datacenter to Azure. The CFO points out that Microsoft purchases servers, networking equipment, and cooling systems in enormous quantities, enabling them to negotiate lower prices from hardware vendors. The company expects to benefit from these lower hardware costs as it migrates. Which cloud computing benefit does this scenario primarily describe?

Accepted Answer

Economies of scale. The scenario describes how Microsoft's massive purchasing power reduces per-unit costs for hardware like servers and cooling systems, which is the definition of economies of scale. This benefit is passed to customers through lower Azure service prices, not through any operational or architectural feature of the cloud itself.

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Elasticity

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High availability

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Measured service