AZ-900 Describe cloud concepts Practice Test 14 — 15 Questions

Question 1

Which Azure cloud benefit allows a company to avoid predicting exactly how much compute capacity it needs months in advance?

Accepted Answer

Elasticity. Elasticity is the Azure cloud benefit that allows a company to automatically scale compute resources up or down based on real-time demand, eliminating the need to predict capacity months in advance. With Azure Virtual Machine Scale Sets or Azure App Service auto-scale, resources can be added or removed dynamically, ensuring you only pay for what you use. This contrasts with traditional on-premises capacity planning, where over-provisioning or under-provisioning is common.

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Fault tolerance

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Geo-redundancy

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Economies of scale

Question 2

Which of the following is a characteristic of the public cloud deployment model?

Accepted Answer

Infrastructure is owned by the provider and shared among multiple customers. In the public cloud deployment model, the cloud provider owns and manages the physical infrastructure (servers, storage, networking), and that infrastructure is shared among multiple customer organizations (tenants). This multi-tenant architecture is a defining characteristic, enabling economies of scale and on-demand resource allocation. Option C correctly identifies this shared, provider-owned model.

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All hardware is owned and managed by the customer

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Resources are dedicated to a single customer organization

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Computing resources are hosted in the customer's own data center

Question 3

According to Microsoft, which factor does NOT affect the SLA percentage for an Azure service?

Accepted Answer

The number of users concurrently accessing the service. The SLA percentage for an Azure service is determined by factors such as redundancy, fault tolerance, and resource configuration, not by the number of concurrent users. Microsoft's SLAs are based on uptime guarantees tied to architectural choices like availability zones, disk types, and availability sets, while user load is managed through scaling and is not a factor in the SLA calculation.

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Whether resources are deployed across availability zones

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Whether Premium SSD or Standard HDD disks are used for VMs

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Whether a single VM or availability set is used

Question 4

Which of the following best describes Platform as a Service (PaaS)?

Accepted Answer

The provider manages hardware and OS while customers manage their applications and data. Platform as a Service (PaaS) provides a managed hosting environment where the cloud provider handles the underlying infrastructure, including hardware, virtualization, operating system, and middleware. The customer is responsible only for deploying and managing their applications and data, making option B correct because it accurately describes this division of responsibility.

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The customer manages everything including hardware and networking

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The customer accesses a complete application managed entirely by the provider

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The provider manages physical servers while customers manage OS and applications

Question 5

What is disaster recovery in the context of cloud computing?

Accepted Answer

Restoring systems and data after a catastrophic event with minimal downtime. Disaster recovery (DR) in cloud computing focuses on restoring systems, applications, and data after a catastrophic event (e.g., natural disaster, cyberattack) to meet Recovery Time Objective (RTO) and Recovery Point Objective (RPO) targets. Azure Site Recovery orchestrates replication, failover, and failback of workloads between primary and secondary regions, ensuring minimal downtime and data loss. This is distinct from high availability, which prevents outages, or auto-scaling, which handles demand fluctuations.

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Preventing any service outages from occurring

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Automatically scaling resources when demand increases

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Distributing traffic across multiple servers for performance

Question 6

What does 'geo-distribution' mean in cloud computing?

Accepted Answer

Deploying applications and data across multiple geographic locations worldwide. Geo-distribution in cloud computing refers to deploying applications, data, and services across multiple geographically separated data centers or regions. This ensures low latency for users worldwide, improves availability through redundancy, and supports disaster recovery by isolating failures to a single region. Azure implements this through paired regions and traffic routing policies like performance-based routing in Azure Traffic Manager.

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Distributing compute resources across multiple virtual machines in a single data center

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Routing network traffic to the fastest available server

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Encrypting data before sending it over the network

Question 7

What is the key difference between capital expenditure (CapEx) and operational expenditure (OpEx) in the context of cloud computing?

Accepted Answer

CapEx is upfront investment in owned infrastructure; OpEx is ongoing pay-as-you-go service costs. Capital expenditure (CapEx) involves a large upfront investment to purchase and own physical infrastructure (servers, storage, networking), while operational expenditure (OpEx) represents ongoing, consumption-based costs where you pay only for the resources you use (e.g., per-hour VM billing, per-GB storage fees). In cloud computing, the shift from CapEx to OpEx is a fundamental financial model change, enabling organizations to avoid large capital outlays and instead align costs with actual usage.

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CapEx is for cloud spending; OpEx is for on-premises spending

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CapEx and OpEx are identical in cloud environments

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OpEx covers hardware costs; CapEx covers software licensing costs

Question 8

What is the difference between vertical scaling and horizontal scaling?

Accepted Answer

Vertical scaling increases a single resource's capacity; horizontal scaling adds more instances. Vertical scaling (scaling up) increases the capacity of a single resource, such as adding more RAM, CPU, or disk space to a virtual machine. Horizontal scaling (scaling out) adds more instances of a resource, distributing the load across multiple machines. This distinction is fundamental in cloud computing, where Azure Virtual Machine Scale Sets exemplify horizontal scaling by automatically adding VM instances, while resizing a VM to a larger SKU represents vertical scaling.

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Vertical scaling adds more instances; horizontal scaling increases instance size

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Both vertical and horizontal scaling achieve the same result through different means

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Vertical scaling is for storage; horizontal scaling is for compute

Question 9

What is 'fault tolerance' in cloud computing?

Accepted Answer

The ability to continue operating correctly despite component failures. Fault tolerance in cloud computing refers to a system's ability to continue operating correctly, without interruption, even when one or more of its components fail. This is achieved through redundancy—such as duplicate hardware, software, or data paths—so that if a component fails, another automatically takes over without any impact on the user. It is a core design principle for high-availability systems, ensuring zero downtime despite failures.

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The ability to automatically scale resources during peak usage

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The ability to restore data after a major disaster

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The ability to deploy applications in multiple geographic regions

Question 10

Which cloud concept allows businesses to deploy applications to global markets quickly without building physical infrastructure in those locations?

Accepted Answer

Global reach through cloud infrastructure. Global reach through cloud infrastructure enables businesses to deploy applications in multiple geographic regions using the cloud provider's existing data centers, eliminating the need to build and manage physical infrastructure in each target market. Providers like Azure offer region pairs and geographies that allow low-latency access and compliance with local data residency requirements, enabling rapid global expansion.

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Elasticity

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Capital expense avoidance

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Fault tolerance

Question 11

Which of the following is NOT a benefit of moving to the cloud?

Accepted Answer

Elimination of internet connectivity requirements. Moving to the cloud does not eliminate the need for internet connectivity; in fact, cloud services are accessed over the internet or dedicated network connections. Option B is correct because it presents a false benefit—cloud computing still requires network connectivity to reach the provider's endpoints, and without it, resources become inaccessible. The other options are legitimate benefits: faster provisioning, global data center reach, and converting CapEx to OpEx.

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Reduced time to provision new resources

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Access to a global network of data centers

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Conversion of capital expenses to operational expenses

Question 12

Which statement correctly describes the operational cost model of cloud computing?

Accepted Answer

You pay for cloud resources only when you consume them, on a recurring basis. Cloud computing follows an operational expenditure (OpEx) model where you pay only for the resources you actually consume, such as compute hours, storage GB-months, or data transfer, on a recurring basis. This eliminates the need for large upfront capital investments and allows you to scale costs with usage, aligning with the pay-as-you-go pricing model central to Azure and other cloud providers.

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You make large upfront investments in hardware that you own and depreciate

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You purchase cloud capacity in bulk at the beginning of each year

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You lease physical servers from the cloud provider for a fixed monthly fee

Question 13

What is Software as a Service (SaaS)?

Accepted Answer

A model where the provider delivers complete software applications managed entirely by the provider. Software as a Service (SaaS) is a cloud computing model where the provider hosts and manages the entire software application, including the underlying infrastructure, middleware, and data. Customers access the application over the internet (typically via a web browser or API) without needing to install, maintain, or update anything locally. This model shifts all operational responsibility to the provider, making it the most 'hands-off' cloud service model for the customer.

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A model where customers manage their own virtual machines and applications

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A model where customers deploy their code on provider-managed platforms

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A model where customers rent physical hardware from the provider

Question 14

Which statement best describes the concept of 'predictability' as a cloud benefit?

Accepted Answer

Confidence in consistent performance and the ability to forecast costs accurately. Predictability in cloud computing refers to the ability to rely on consistent performance and accurately forecast costs. This is achieved through Azure's Service Level Agreements (SLAs) that guarantee uptime and performance metrics, combined with tools like Azure Cost Management and Pricing Calculator that provide transparent, granular cost estimates. This allows organizations to plan budgets and resource allocation with confidence, avoiding unexpected expenses or performance degradation.

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The ability to automatically replace failed resources without human intervention

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The guarantee that all data is stored within a specific geographic region

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The ability to deploy identical environments for development and production

Question 15

Which of the following is an example of a SaaS (Software as a Service) offering from Microsoft?

Accepted Answer

Microsoft 365. Microsoft 365 is a SaaS offering because it provides ready-to-use productivity applications (e.g., Word, Excel, Teams) accessed via a web browser or client, with Microsoft managing the underlying infrastructure, operating system, and application updates. The customer simply consumes the software without needing to install or maintain servers or runtime environments.

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Azure Virtual Machines

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Azure App Service

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Azure SQL Database