AZ-900 Describe cloud concepts Practice Test 3 — 15 Questions

Question 1

A startup wants to run a web application without managing the underlying servers. They only want to upload their code and let the cloud provider handle the runtime, scaling, and maintenance. Which cloud service model is this?

Accepted Answer

Platform as a Service (PaaS). Platform as a Service (PaaS) is the correct model because it provides a managed hosting environment where the startup can deploy their web application code without managing the underlying servers, operating systems, or runtime infrastructure. Azure App Service is a prime example of PaaS, handling automatic scaling, patching, and load balancing while the customer only focuses on code and data.

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Infrastructure as a Service (IaaS)

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Software as a Service (SaaS)

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Function as a Service (FaaS)

Question 2

A company is evaluating cloud providers. They want to ensure that their data remains within a specific country due to legal requirements. Which cloud computing concept is most directly related to this requirement?

Accepted Answer

Data sovereignty. Data sovereignty is the concept that data is subject to the laws and governance structures of the country where it is physically stored. For a company with legal requirements to keep data within a specific country, this concept directly dictates where cloud providers must locate their data centers and how they handle data residency. Azure, for example, offers region pairs and data residency commitments through its Trust Center to help customers meet such compliance obligations.

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Latency

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High availability

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Elasticity

Question 3

A company runs a web application that experiences unpredictable traffic spikes. They want the cloud to automatically increase the number of virtual machine instances during high demand and decrease them when demand drops, without manual intervention. Which cloud computing characteristic does this describe?

Accepted Answer

Elasticity. Elasticity is the ability of a cloud system to dynamically scale resources up and down based on real-time demand. Scalability refers to the ability to handle growth but may not be automatic. High availability focuses on uptime, and fault tolerance ensures operation during failures. This scenario specifically describes automatic scaling, which is elasticity.

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Scalability

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High availability

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Fault tolerance

Question 4

A hospital stores patient data in the cloud. The hospital is responsible for encrypting the data before uploading, managing user access, and complying with healthcare regulations. The cloud provider is responsible for securing the physical datacenter, network infrastructure, and hypervisor. This model describes which concept?

Accepted Answer

Shared responsibility model. The scenario explicitly divides security responsibilities between the hospital (data encryption, access management, regulatory compliance) and the cloud provider (physical datacenter, network, hypervisor). This division of security obligations is the core definition of the shared responsibility model, which applies across all cloud service models (IaaS, PaaS, SaaS) but is most clearly illustrated here where the customer retains control over data and identity layers.

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Infrastructure as a Service (IaaS)

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Platform as a Service (PaaS)

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Software as a Service (SaaS)

Question 5

A company is migrating its on-premises workloads to Azure. Previously, they purchased servers every three years as a large capital investment. Now, they pay a monthly subscription for virtual machines based on actual usage, with no long-term commitment. Which type of cloud expenditure model does this represent?

Accepted Answer

Capital expenditure (CapEx) to operational expenditure (OpEx). This scenario describes a shift from Capital Expenditure (CapEx), where the company made large upfront investments in hardware every three years, to Operational Expenditure (OpEx), where they pay a monthly subscription for Azure virtual machines based on actual usage with no long-term commitment. This is a core benefit of cloud computing, converting fixed, upfront costs into variable, ongoing expenses that align with consumption.

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Operational expenditure (OpEx) to capital expenditure (CapEx)

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Pay-as-you-go to reserved

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Consumption-based to fixed cost

Question 6

A company wants to run some applications in its own on-premises datacenter for compliance reasons, while also using cloud services for burst capacity and development/testing. Which cloud deployment model should they adopt?

Accepted Answer

Hybrid cloud. The hybrid cloud model is correct because it combines on-premises infrastructure (private cloud) with public cloud services, enabling the company to keep sensitive applications in its own datacenter for compliance while using the public cloud for burst capacity and development/testing. This directly matches the scenario's requirement for a unified environment that spans both local and cloud resources.

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Private cloud

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Public cloud

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Community cloud

Question 7

An Azure service guarantees 99.95% uptime for virtual machines deployed with two or more instances in an availability set. If the monthly uptime falls below this percentage, customers can receive a service credit. What does this guarantee represent?

Accepted Answer

Service Level Agreement (SLA). This guarantee is a Service Level Agreement (SLA) because it is a formal, published commitment from Microsoft regarding the uptime percentage (99.95%) for a specific Azure service (Virtual Machines in an Availability Set), and it includes a financial remedy (service credits) if the commitment is not met. SLAs are contractual agreements that define the level of service a customer can expect and the compensation for failures.

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Service Level Objective (SLO)

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Service Level Indicator (SLI)

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Service Health

Question 8

A company currently budgets for maximum capacity to handle peak loads, resulting in underutilized resources during off-peak times. They want a model where they can quickly adjust resources up or down based on demand. Which cloud characteristic directly addresses this concern?

Accepted Answer

Elasticity. Elasticity is the cloud characteristic that enables automatic scaling of resources up or down in response to real-time demand. This directly addresses the company's need to avoid over-provisioning for peak loads while still being able to handle spikes without manual intervention, typically implemented through auto-scaling policies in services like Azure Virtual Machine Scale Sets or Azure App Service autoscale.

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High availability

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Geo-redundancy

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Fault tolerance

Question 9

A company wants to use cloud services to temporarily increase compute capacity for a promotional event, then reduce resources afterward. They want to pay only for the extra resources used during that event. Which cloud benefit does this scenario best describe?

Accepted Answer

Scalability. This scenario describes scalability, specifically the ability to scale out (increase capacity) for a promotional event and then scale in (reduce resources) afterward, paying only for what is used. Azure Auto Scaling (e.g., Virtual Machine Scale Sets or Azure App Service autoscale) automatically adjusts compute resources based on demand, aligning with the pay-as-you-go model. The key is that resources are temporarily increased and then reduced, which is the hallmark of scalability, not just the ability to handle load.

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High availability

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Agility

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Reliability

Question 10

A hospital is migrating patient data to the cloud. The hospital is responsible for managing who can access the data and for encrypting the data before upload. The cloud provider is responsible for securing the physical datacenters, network infrastructure, and hypervisor. This division of security responsibilities is described by which model?

Accepted Answer

Shared responsibility model. The shared responsibility model defines the division of security obligations between the cloud provider and the customer. In this scenario, the hospital (customer) is responsible for identity and access management (IAM) and data encryption at rest and in transit, while the cloud provider secures the physical datacenter, network infrastructure, and hypervisor. This clear separation of duties is the core of the shared responsibility model, which varies by service model (IaaS, PaaS, SaaS).

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Defense in depth

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Principle of least privilege

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Zero trust model

Question 11

A company pays a monthly subscription fee for cloud services based on the resources they consume, such as the number of virtual machines or amount of storage used. There are no upfront costs or fixed long-term commitments. This pricing model is known as:

Accepted Answer

Pay-as-you-go. Pay-as-you-go (also called consumption-based pricing) is the correct model because it charges the customer only for the actual resources consumed (e.g., VM hours, storage GBs) with no upfront payment or termination penalties. This aligns directly with the scenario of a monthly subscription fee based on resource usage without long-term commitments.

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Reserved instances

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Spot pricing

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Hybrid benefit

Question 12

A company wants to move their on-premises infrastructure to the cloud to avoid the large upfront cost of purchasing new servers every three years. In the cloud, they will pay only for the server capacity they use, with no long-term commitment. This shift from upfront investment to variable expense is an example of which cloud benefit?

Accepted Answer

Consumption-based pricing. Consumption-based pricing is a cloud model where customers pay only for the resources they actually use (e.g., compute hours, storage GBs) with no upfront costs or long-term commitments. This directly matches the scenario of avoiding large upfront server purchases and paying only for capacity used, shifting from a capital expenditure (CapEx) to an operational expenditure (OpEx) model.

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Economies of scale

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Capacity planning

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Reserved capacity

Question 13

A company wants to move from an on-premises data center to Azure. They currently budget for purchasing servers, networking equipment, and software licenses as a one-time capital expense. In Azure, they will pay a monthly fee based on the resources they use. What type of cloud benefit does this represent?

Accepted Answer

Operational expenditure (OpEx). Option C is correct because moving from a capital expense (CapEx) model—where servers, networking gear, and licenses are purchased upfront—to a pay-as-you-go monthly fee in Azure represents a shift to operational expenditure (OpEx). This cloud benefit allows the company to avoid large upfront investments and instead pay for only the compute, storage, and network resources consumed, aligning costs with usage.

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High availability

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Scalability

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Fault tolerance

Question 14

A startup application experiences unpredictable traffic spikes. The application runs on Azure Virtual Machines. They want the VMs to automatically increase in number during peak times and decrease during low usage, without manual intervention. Which cloud characteristic does this requirement describe?

Accepted Answer

Elasticity. Elasticity is the cloud characteristic that enables resources to automatically scale out (increase) during high demand and scale in (decrease) during low demand, matching capacity to workload in real time. In this scenario, Azure Virtual Machines can be configured with autoscale rules (e.g., based on CPU > 75% for 5 minutes) to add or remove VM instances without manual intervention. This directly addresses the startup's need to handle unpredictable traffic spikes while optimizing cost.

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High availability

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Disaster recovery

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Geo-redundancy

Question 15

A company is evaluating cloud providers and needs to ensure that their data remains within a specific geographic boundary due to data sovereignty laws. Which cloud concept is most directly related to this requirement?

Accepted Answer

Region. Azure regions are discrete geographic locations containing one or more datacenters that provide the physical boundary for data residency. By deploying resources within a specific region (e.g., 'West Europe'), an organization ensures that data is stored and processed within that geographic boundary, directly addressing data sovereignty laws. Other concepts like Availability Zones or Latency do not enforce geographic data residency.

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Availability Zone

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Latency

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Compliance