AZ-900 Describe cloud concepts Practice Test 12 — 15 Questions

Question 1

A financial institution must keep sensitive customer financial data on-premises to comply with regulatory requirements. However, they also want to use Azure to run compute-intensive analytics on anonymized datasets, taking advantage of scalable resources without managing physical servers. Which cloud deployment model should they adopt?

Accepted Answer

Hybrid cloud. The hybrid cloud model is correct because it allows the financial institution to keep sensitive customer data on-premises for regulatory compliance while leveraging Azure's public cloud for compute-intensive analytics on anonymized datasets. This approach combines the security and control of a private cloud (on-premises) with the scalability and managed services of a public cloud, without requiring the organization to manage physical servers for the analytics workload.

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Public cloud

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Private cloud

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Community cloud

Question 2

A company runs a web application on Azure. At the end of each month, the finance team reviews an invoice that itemizes charges by resource type, such as virtual machine compute hours, storage capacity used, and data transfer volume. The total cost directly corresponds to the exact quantity of resources consumed during the billing period. This capability is an example of which fundamental characteristic of cloud computing?

Accepted Answer

Measured service. Measured service is the correct answer because it refers to the cloud provider's ability to meter and bill customers based on actual resource consumption. In this scenario, the invoice itemizes charges by resource type (compute hours, storage, data transfer) and the total cost directly corresponds to the exact quantity consumed, which is the defining characteristic of measured service. This capability relies on metering telemetry (e.g., Azure Monitor metrics, usage logs) to track usage and generate a pay-per-use billing model.

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Rapid elasticity

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Resource pooling

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On-demand self-service

Question 3

A company deploys a mission-critical application across three Azure availability zones. The application is designed to continue operating without any interruption if an entire availability zone becomes unavailable. Which cloud computing characteristic does this scenario best illustrate?

Accepted Answer

Fault tolerance. B is correct because fault tolerance is the ability of a system to continue operating without any interruption when a component fails. Deploying a mission-critical application across three Azure availability zones ensures that if an entire zone goes down, the application remains operational with zero downtime, which is the defining characteristic of fault tolerance.

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Elasticity

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High availability

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Scalability

Question 4

A company runs an e-commerce web application on Azure virtual machines that are part of a virtual machine scale set configured with an autoscale rule based on CPU utilization. During a flash sale, customer traffic surges, causing the average CPU utilization across all instances to exceed 75% for five minutes. The scale set automatically provisions three additional VM instances to handle the increased load. After the sale ends, traffic normalizes, CPU utilization drops below 30%, and the scale set automatically removes the extra instances. This scenario best illustrates which characteristic of cloud computing?

Accepted Answer

Elasticity. Elasticity is the ability of a cloud system to dynamically scale resources up or down based on demand. In this scenario, the virtual machine scale set automatically adds three VM instances when CPU utilization exceeds 75% for five minutes and removes them when utilization drops below 30%, demonstrating rapid, automated scaling to match workload changes.

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High availability

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Fault tolerance

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Disaster recovery

Question 5

A company hosts a customer relationship management (CRM) application on Azure virtual machines. The sales team needs to access the CRM from various locations, including the airport, home, and client offices, using company-issued laptops and personal mobile devices. The application is accessible via a standard web browser over the internet without requiring any special client software or dedicated network connections. Which fundamental characteristic of cloud computing does this scenario primarily demonstrate?

Accepted Answer

Broad network access. The scenario describes users accessing the CRM application from various locations (airport, home, client offices) using different devices (company laptops and personal mobile phones) over the internet via a standard web browser without special client software or dedicated network connections. This directly maps to the cloud computing characteristic of broad network access, which is defined by NIST SP 800-145 as resources that are available over the network and accessed through standard mechanisms (e.g., web browsers, HTTPS) that promote use by heterogeneous client platforms (e.g., mobile phones, laptops, workstations).

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On-demand self-service

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Resource pooling

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Rapid elasticity

Question 6

A company migrates its on-premises servers to Azure virtual machines (IaaS model). The security team is planning the patching strategy and asks who is responsible for installing security updates on the guest operating system of the Azure VMs. According to the shared responsibility model, which statement is correct?

Accepted Answer

The customer is responsible for maintaining and patching the guest operating system on Azure virtual machines.. In the shared responsibility model for IaaS, the customer retains control over the guest operating system, applications, and data. Microsoft manages the physical host, hypervisor, and underlying Azure infrastructure, but the customer must install and maintain security updates on the guest OS of their Azure VMs. This is because the customer has full administrative access to the VM and is responsible for its configuration and patch management.

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Microsoft is responsible for maintaining and patching the guest operating system on Azure virtual machines.

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Microsoft is responsible for patching any application software that runs on Azure virtual machines.

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The customer is responsible for the physical security of the Azure datacenter where the virtual machines are hosted.

Question 7

A company is migrating its on-premises infrastructure to Azure. Previously, the company purchased physical servers, networking equipment, and data center space every three years, paying a large sum upfront. After migration, the company expects to pay a monthly invoice based only on the virtual machines and storage it actually uses, with the ability to increase or decrease resources as needed without additional upfront costs. This change in cost structure is best described by which pair of cloud computing concepts?

Accepted Answer

Capital expenditure (CapEx) to operational expenditure (OpEx). This scenario describes a shift from paying large upfront sums for hardware and data center space (CapEx) to paying a monthly invoice based on actual consumption of virtual machines and storage (OpEx). Azure's pay-as-you-go model allows resources to be scaled up or down without upfront costs, directly aligning with the CapEx-to-OpEx transition. This is a fundamental cloud concept that changes how organizations budget and manage IT expenses.

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Measured service and resource pooling

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Economies of scale and geographic distribution

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Agility and high availability

Question 8

A company's IT manager is evaluating a public cloud provider. The provider's data center contains powerful physical servers that host virtual machines from thousands of different organizations. The manager is concerned about security, but the provider assures that each organization's VMs are logically isolated and cannot access each other's data, even though they share the same hardware. Which essential characteristic of cloud computing does this scenario best describe?

Accepted Answer

Resource pooling. The scenario describes resource pooling because the provider's physical servers host VMs from multiple organizations, and logical isolation ensures each tenant's data remains separate. Resource pooling is the cloud characteristic where computing resources (e.g., storage, processing, memory) are aggregated to serve multiple customers using a multi-tenant model, with physical and virtual resources dynamically assigned and reassigned according to demand. The provider's assurance of logical isolation (e.g., via hypervisor-level segmentation or VLANs) is a direct implementation of resource pooling's security boundary.

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Rapid elasticity

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Measured service

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Broad network access

Question 9

A company is migrating its on-premises infrastructure to Azure. In the past, to provision a new server, the IT team had to submit a formal request to the data center operations team. The operations team would then procure hardware, install the operating system, configure networking, and make the server available. This process often took several weeks. After migrating to Azure, a developer can log into the Azure portal, select a virtual machine configuration, and have it provisioned and running within minutes, without any need to interact with Azure support or operations staff. Which essential characteristic of cloud computing does this scenario best illustrate?

Accepted Answer

On-demand self-service. The scenario describes a developer provisioning a virtual machine directly through the Azure portal without any human intervention from IT or operations staff. This aligns with the cloud characteristic of on-demand self-service, where users can provision and manage computing resources as needed automatically, without requiring manual approval or interaction with service providers.

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Rapid elasticity

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Resource pooling

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Measured service

Question 10

A company provides a software-as-a-service (SaaS) application to multiple enterprise customers. Each customer's usage of compute and storage resources is tracked separately. At the end of each month, the company generates detailed invoices that reflect each customer's exact resource consumption, including CPU hours, storage GB-months, and data transfer. The cloud provider automatically measures all resource usage and makes the data available through an API. Which essential characteristic of cloud computing does this scenario primarily demonstrate?

Accepted Answer

Measured service. The scenario describes a SaaS provider that tracks each customer's exact resource consumption (CPU hours, storage GB-months, data transfer) and generates invoices based on that metered usage. This aligns directly with the 'measured service' characteristic of cloud computing, where resource usage is automatically monitored, controlled, and reported, providing transparency for both the provider and consumer. The cloud provider's API making usage data available is a key enabler of this metering and billing capability.

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On-demand self-service

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Broad network access

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Resource pooling

Question 11

A company runs a web application on an Azure virtual machine. The application experiences periodic traffic surges during promotional campaigns. To handle the increased load, the IT team manually changes the VM size from Standard_D2s_v3 to Standard_D8s_v3 before each campaign and then changes it back after the campaign ends. Which cloud computing concept does this scenario exemplify?

Accepted Answer

Scalability. This scenario exemplifies scalability, specifically vertical scaling (scaling up), because the IT team manually increases the VM size to handle higher demand and then reduces it afterward. Scalability is the ability to adjust resources to meet changing workload demands, which is exactly what occurs when changing from Standard_D2s_v3 to Standard_D8s_v3.

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Elasticity

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High availability

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Disaster recovery

Question 12

A retail company runs an e-commerce application on Azure virtual machines. Traffic follows a predictable daily pattern: peak load occurs from 9 AM to 5 PM on weekdays. To handle this, the company configures an Azure autoscale rule that adds virtual machines at 8:30 AM and removes them at 5:30 PM each weekday. This scenario best demonstrates which cloud computing characteristic?

Accepted Answer

Elasticity. Elasticity is the ability to dynamically scale resources up or down to match demand. In this scenario, the autoscale rule adds VMs at 8:30 AM to handle the predictable peak load and removes them at 5:30 PM, demonstrating automatic resource provisioning and de-provisioning based on a schedule. This is a textbook example of elasticity in cloud computing.

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High availability

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Agility

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Fault tolerance

Question 13

A company migrates its web application to Azure App Service (PaaS) and its data to Azure SQL Database (PaaS). The company wants to understand which security responsibilities it retains after the migration. According to the shared responsibility model, which of the following responsibilities remains the responsibility of the company (customer) when using these PaaS services?

Accepted Answer

Managing user access to the application and database. In the shared responsibility model for PaaS, the cloud provider manages the underlying infrastructure, including the OS and network security groups, while the customer retains responsibility for managing access to their application and data. For Azure App Service and Azure SQL Database, this means the customer must configure authentication, authorization, and user permissions (e.g., using Azure Active Directory or SQL logins) to control who can access the application and database.

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Patching the operating system of the web server

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Managing network security groups for the virtual network

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Physical security of the Azure data center

Question 14

A small start-up company needs to run complex machine learning training jobs that require powerful GPU instances for only a few hours each day. The company cannot afford the high upfront capital expense of purchasing and maintaining multiple GPU servers on-premises. Instead, they spin up GPU-optimized virtual machines on Azure during training hours and delete them when the jobs finish, paying only for the compute time consumed. Which benefit of cloud computing does this scenario primarily illustrate?

Accepted Answer

Consumption-based pricing. The scenario describes the company spinning up GPU-optimized VMs only when needed and deleting them after use, paying solely for the compute time consumed. This directly illustrates consumption-based pricing (also known as pay-as-you-go), a core cloud benefit where customers pay only for the resources they actually use, avoiding large upfront capital expenditures. The ability to scale down to zero when not in use is a hallmark of this model, enabling cost efficiency for intermittent workloads.

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High availability

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Fault tolerance

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Geographic distribution

Question 15

A company runs an e-commerce web application on a set of Azure virtual machines behind a load balancer. The application experiences unpredictable traffic surges during flash sales. The company configures an autoscale setting that automatically adds virtual machines when the average CPU usage across the existing VMs exceeds 75% for five minutes, and removes virtual machines when CPU usage drops below 30% for ten minutes. Which essential characteristic of cloud computing does this configuration primarily demonstrate?

Accepted Answer

Rapid elasticity. B is correct because the autoscale configuration dynamically adds and removes virtual machines in response to real-time CPU usage thresholds, which is the defining characteristic of rapid elasticity. This allows the e-commerce application to scale computing resources up and down automatically and seamlessly to match unpredictable traffic surges, ensuring performance during flash sales without manual intervention.

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Measured service

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Resource pooling

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Broad network access