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

Question 1

Which cloud benefit helps organizations meet workload demands during unexpected events like viral marketing campaigns without service degradation?

Accepted Answer

Elasticity. Elasticity is the correct answer because it refers to the ability of a cloud system to automatically provision and de-provision resources (such as compute instances, storage, or bandwidth) in real time to match fluctuating demand. During a viral marketing campaign, traffic spikes can be handled by scaling out resources dynamically, ensuring consistent performance without manual intervention or service degradation.

Answer

High availability

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Security

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Predictability

Question 2

When using Azure, a company wants to calculate the composite SLA for two services used together where both must be available. Service A has a 99.9% SLA and Service B has a 99.95% SLA. What is the composite SLA?

Accepted Answer

Approximately 99.85%. When two services must both be available (an 'and' scenario), the composite SLA is calculated by multiplying their individual SLAs. Service A at 99.9% (0.999) and Service B at 99.95% (0.9995) gives 0.999 × 0.9995 = 0.9985005, which rounds to approximately 99.85%. This reflects the increased probability of failure when multiple dependencies are required.

Answer

99.95% (the higher of the two SLAs)

Answer

99.9% (the lower of the two SLAs)

Answer

100% because Azure guarantees maximum availability

Question 3

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 4

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 5

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 6

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.

Answer

Paying a fixed monthly fee regardless of actual resource usage

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Purchasing capacity upfront for a year at a discounted rate

Answer

Paying a per-user license fee for cloud software access

Question 7

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 8

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.

Answer

Cloud eliminates the need for disaster recovery planning entirely

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

Answer

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

Question 9

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.

Answer

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 10

A company runs a batch job every night that takes 4 hours and cannot be interrupted. Which VM pricing model provides the lowest cost for this workload?

Accepted Answer

Pay-as-you-Go Instances. Pay-as-you-go pricing is the most cost-effective for a nightly 4-hour batch job because it charges only for the time the VM runs, without requiring an upfront commitment. Reserved Instances are designed for always-on workloads; using them for only 4 hours per night would waste the paid capacity during idle hours, making Pay-as-you-go cheaper for intermittent usage.

Answer

Spot VMs

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Reserved Instances (1 or 3-year)

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Dedicated Hosts

Question 11

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.

Answer

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

Answer

SLA percentage has no practical impact on allowed downtime

Answer

All Azure services provide the same SLA regardless of configuration

Question 12

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 13

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 14

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 15

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.

Answer

99.9%

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99.99%

Answer

100%