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

Question 1

What is the primary difference between a public cloud and a private cloud?

Accepted Answer

Public cloud infrastructure is shared among multiple customers; private is dedicated to one organization. The primary difference is that a public cloud uses a multi-tenant architecture where infrastructure resources like compute, storage, and networking are shared across multiple unrelated customers, while a private cloud provisions dedicated infrastructure for a single organization, either on-premises or hosted by a third party. This distinction is fundamental to cloud deployment models as defined by NIST SP 800-145, which emphasizes resource pooling in public clouds versus single-tenant isolation in private clouds.

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Public cloud is more secure than private cloud

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Private cloud is always hosted by a third-party provider

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Public cloud can only be accessed from within the organization's network

Question 2

Which cloud concept refers to the ability to recover quickly from a failure without impacting user experience?

Accepted Answer

Reliability. Reliability is the cloud concept that ensures a system can recover quickly from failures, such as hardware crashes or network outages, without noticeable impact on end users. This is achieved through redundancy, fault tolerance, and automated failover mechanisms, which maintain service continuity and uptime as defined in SLAs.

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Scalability

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Agility

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Cost efficiency

Question 3

Which benefit of cloud computing allows developers to test and deploy applications globally in minutes?

Accepted Answer

Speed and agility in global deployment. Cloud computing enables rapid global deployment through a distributed infrastructure of data centers and content delivery networks (CDNs). Developers can replicate applications across multiple regions in minutes using automated deployment pipelines and infrastructure-as-code tools, eliminating the need to provision physical servers in each location.

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Economies of scale

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Fault tolerance

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Predictable pricing

Question 4

In cloud computing, what does 'consumption-based pricing' mean?

Accepted Answer

Paying only for the resources you actually use, measured by time, amount, or transactions. Consumption-based pricing is a cloud billing model where you pay only for the resources you consume, measured by metrics such as compute hours, storage GB-months, or number of transactions. This aligns with the operational expenditure (OpEx) model, allowing you to scale costs with usage without upfront commitments. Microsoft Azure implements this through pay-as-you-go pricing, where you are billed at the end of each billing cycle based on metered usage.

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Paying a fixed monthly fee regardless of actual resource usage

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Purchasing capacity upfront for a year at a discounted rate

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Paying a per-user license fee for cloud software access

Question 5

What is 'serverless computing'?

Accepted Answer

A model where developers deploy code without managing server infrastructure, paying only for execution. Serverless computing is a cloud execution model where the cloud provider dynamically manages the allocation and provisioning of servers. Developers write and deploy code in the form of functions (e.g., AWS Lambda, Azure Functions) without provisioning or managing any underlying server infrastructure, and they are billed only for the actual compute time consumed during execution, not for idle capacity.

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Computing that uses no physical servers anywhere in the world

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Running applications without an operating system

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Hosting applications on shared physical hardware

Question 6

How does cloud computing help with disaster recovery compared to traditional on-premises approaches?

Accepted Answer

Cloud enables geographic redundancy and automated failover at lower cost than traditional DR. Cloud computing supports disaster recovery by enabling geographic redundancy and automated failover across multiple Azure regions at a fraction of the cost of building and maintaining a secondary on-premises data center. Services like Azure Site Recovery and Azure Traffic Manager allow organizations to replicate workloads and automatically redirect traffic to a secondary region during an outage, reducing both recovery time objective (RTO) and recovery point objective (RPO) without the capital expenditure of a dedicated DR site.

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Cloud eliminates the need for disaster recovery planning entirely

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Cloud disaster recovery always provides faster recovery than on-premises DR

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Cloud providers guarantee zero data loss in the event of a disaster

Question 7

What is the shared responsibility model in cloud computing?

Accepted Answer

A framework dividing security responsibilities between the cloud provider and the customer. The shared responsibility model defines the division of security and compliance obligations between the cloud provider and the customer. The provider is responsible for the security 'of' the cloud (physical hosts, network, hypervisor), while the customer is responsible for security 'in' the cloud (data, access management, OS configuration). This division varies by service model (IaaS, PaaS, SaaS), but the core principle is that security is a shared, not transferred, responsibility.

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The provider and customer each pay half the cost of cloud services

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An agreement where customers share their infrastructure with other cloud users

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A service where two cloud providers share management of customer workloads

Question 8

Which statement accurately describes the relationship between availability and SLA percentage?

Accepted Answer

Higher SLA percentages mean less allowed downtime and typically require more redundancy. B is correct because SLA (Service Level Agreement) percentage directly correlates to the maximum allowed downtime. A higher SLA percentage, such as 99.99% versus 99%, permits less downtime per year (approximately 52.56 minutes vs. 3.65 days). To achieve higher SLAs, Azure requires implementing redundancy across availability zones or regions, as a single instance typically cannot meet the uptime guarantee.

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A 99.9% SLA allows for more downtime per year than a 99% SLA

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SLA percentage has no practical impact on allowed downtime

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All Azure services provide the same SLA regardless of configuration

Question 9

What does 'manageability' mean as a benefit of cloud computing?

Accepted Answer

The ability to manage cloud resources through portal, CLI, APIs, and automated monitoring. Manageability in cloud computing refers to the ability to efficiently administer and control cloud resources through multiple interfaces such as the Azure portal, command-line interface (CLI), APIs, and automated monitoring tools. This allows administrators to deploy, configure, update, and scale resources programmatically or via a web interface without needing physical access to hardware, enabling rapid changes and consistent management across large environments.

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The ability to physically access and repair cloud hardware

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The right to audit the cloud provider's security practices

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The guarantee that resources will always be available

Question 10

What does 'high availability' mean in Azure?

Accepted Answer

Services that remain operational and accessible with minimal planned or unplanned downtime. High availability in Azure refers to the ability of services and resources to remain operational and accessible despite failures, with minimal planned or unplanned downtime. It is achieved through redundancy, fault tolerance, and automatic failover mechanisms, such as Azure Availability Zones and Availability Sets, which ensure that if one component fails, another takes over without significant interruption.

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Resources that are accessible from any device regardless of operating system

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Resources that can be scaled up to handle maximum load

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Data that is encrypted and protected from unauthorized access

Question 11

Which cloud benefit specifically refers to Microsoft's commitment to securing customer data and keeping it private?

Accepted Answer

Security and privacy governance. Microsoft's commitment to securing customer data and keeping it private is encapsulated in the 'Security and privacy governance' benefit. This refers to Microsoft's shared responsibility model and contractual guarantees under the Microsoft Online Services Terms (OST) and the Microsoft Privacy Statement, which ensure that customer data is not used for advertising or mined for AI training without explicit consent. It also includes compliance with global standards like ISO 27001, SOC 2, and GDPR, making it the direct answer to the question.

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Scalability

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Predictable pricing

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Global reach

Question 12

A company runs a web application on two VMs in the same Availability Set. What is the guaranteed SLA for the VMs?

Accepted Answer

99.95%. Microsoft guarantees a 99.95% SLA for two or more virtual machines deployed in the same Availability Set because the set distributes VMs across separate fault domains and update domains, ensuring that at least one VM remains available during planned maintenance or hardware failures. The SLA applies only when all VMs are in the same Availability Set and all disks are managed disks, as per the Azure Compute SLA terms.

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99.9%

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99.99%

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100%

Question 13

Which statement best describes the 'economies of scale' advantage of cloud computing for customers?

Accepted Answer

Cloud providers achieve lower per-unit costs through massive purchasing power, offering customers lower prices. Economies of scale in cloud computing means that cloud providers like AWS, Azure, or Google Cloud operate at a massive scale, allowing them to negotiate bulk discounts on hardware, power, and cooling. These cost savings are passed down to customers in the form of lower pay-as-you-go prices, making it cheaper for individual organizations than running their own on-premises data centers.

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Organizations save money by eliminating all IT staff when using the cloud

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Organizations can use cloud resources without paying anything

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Organizations pay less because cloud resources are lower quality than enterprise hardware

Question 14

What is the Azure concept of 'regions' and why do they matter for applications?

Accepted Answer

Regions are geographic areas affecting data residency, latency, and disaster recovery. Azure regions are geographic areas containing one or more datacenters that provide low-latency networking and data residency control. They matter because deploying applications in the same region as users reduces network latency, and distributing across regions enables disaster recovery and high availability. Additionally, regions enforce data sovereignty by ensuring customer data stays within specified geographic boundaries for compliance.

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Regions determine the maximum number of VMs you can run

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Regions only matter for compliance with local laws and have no performance impact

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All Azure regions offer identical service availability and performance

Question 15

Which type of cloud service model would a company typically use for hosting their own custom web application where they manage the code but not the server operating system?

Accepted Answer

PaaS (Platform as a Service). PaaS (Platform as a Service) is correct because the company manages only the application code and data, while the cloud provider handles the underlying server operating system, runtime, middleware, and infrastructure. This aligns with the scenario where the customer controls the custom web application but not the OS.

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IaaS (Infrastructure as a Service)

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SaaS (Software as a Service)

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FaaS (Function as a Service)