MS-900 Describe cloud concepts — Timed 15 Questions

Question 1

A company is evaluating moving its on-premises infrastructure to a cloud environment. They want a service that provides virtual machines, storage, and networking capabilities while retaining full control over the operating system and applications. Which cloud service model best meets this requirement?

Accepted Answer

Infrastructure as a Service (IaaS). Infrastructure as a Service (IaaS) provides virtualized computing resources, including virtual machines, storage, and networking, over the internet. The customer retains full administrative control over the operating system, applications, and middleware, while the cloud provider manages the underlying physical hardware. This matches the requirement for full OS and application control.

Answer

Software as a Service (SaaS)

Answer

Platform as a Service (PaaS)

Answer

Private Cloud

Question 2

Which characteristic of cloud computing allows a user to provision resources automatically without requiring human interaction with the service provider?

Accepted Answer

On-demand self-service. Option C is correct because on-demand self-service is a fundamental characteristic of cloud computing defined by NIST (SP 800-145) that allows a user to unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider. This is typically implemented through a web portal or API (e.g., AWS Console, Azure Portal, or RESTful APIs) that enables instant resource creation and configuration.

Answer

Rapid elasticity

Answer

Resource pooling

Answer

Measured service

Question 3

A company runs a critical application on-premises but wants to extend capacity to the cloud during peak demand without purchasing additional hardware. Which cloud deployment model best describes this strategy?

Accepted Answer

Hybrid cloud. A hybrid cloud model combines on-premises infrastructure (private cloud) with public cloud resources, enabling a company to 'burst' into the public cloud during peak demand without purchasing additional hardware. This strategy, often called cloud bursting, allows the critical application to run locally under normal conditions and seamlessly extend capacity to a public cloud provider like Azure during spikes.

Answer

Public cloud

Answer

Private cloud

Answer

Multi-cloud

Question 4

A company's CFO is pleased that they only pay for the compute and storage resources consumed each month, with no upfront hardware costs. This billing model is a direct result of which cloud computing characteristic?

Accepted Answer

Measured service. The CFO's observation that the company only pays for consumed compute and storage resources with no upfront hardware costs directly reflects the 'measured service' characteristic of cloud computing. Measured service means cloud providers meter resource usage (e.g., CPU hours, GB-months of storage) and bill based on actual consumption, typically using a pay-as-you-go model. This eliminates the need for capital expenditure on hardware, as costs are operational and tied to usage metrics.

Answer

On-demand self-service

Answer

Broad network access

Answer

Resource pooling

Question 5

A startup wants to focus only on developing and deploying its application code without managing underlying servers or operating systems. Which cloud service model best fits this need?

Accepted Answer

Platform as a Service (PaaS). Platform as a Service (PaaS) is the correct choice because it abstracts the underlying infrastructure, including servers, operating systems, and runtime environments, allowing the startup to focus solely on developing and deploying application code. With PaaS, the cloud provider manages the OS patching, hardware scaling, and middleware, while the customer only manages the application and data. This directly matches the requirement of not managing servers or operating systems.

Answer

Infrastructure as a Service (IaaS)

Answer

Software as a Service (SaaS)

Answer

On-premises deployment

Question 6

An e-commerce application runs in the cloud and automatically adjusts the number of virtual machines based on real-time traffic. When traffic spikes, more VMs are added; when traffic drops, VMs are removed. Which cloud computing characteristic does this behavior exemplify?

Accepted Answer

Rapid elasticity. Rapid elasticity is the cloud characteristic that enables resources to scale out (add VMs) and scale in (remove VMs) automatically in response to real-time demand. In this e-commerce scenario, the application adjusts VM count based on traffic spikes and drops, which directly matches the definition of rapid elasticity as defined by NIST SP 800-145.

Answer

Measured service

Answer

Resource pooling

Answer

On-demand self-service

Question 7

A company runs a legacy application that requires a fixed amount of dedicated hardware resources for compliance reasons. However, they want to benefit from cloud-based backup and disaster recovery to reduce on-premises hardware costs. Which cloud deployment model best aligns with this requirement?

Accepted Answer

Hybrid cloud. Hybrid cloud is correct because it allows the company to keep the legacy application on dedicated on-premises hardware for compliance, while leveraging cloud-based backup and disaster recovery services (e.g., Azure Backup and Azure Site Recovery) to reduce on-premises hardware costs. This model combines private cloud (or on-premises infrastructure) with public cloud resources, enabling data replication and failover to the cloud without migrating the application itself.

Answer

Public cloud

Answer

Private cloud

Answer

Community cloud

Question 8

Which cloud deployment model provides the highest level of control over resources and infrastructure?

Accepted Answer

Private cloud. The private cloud deployment model provides the highest level of control over resources and infrastructure because it is dedicated to a single organization, allowing full customization of hardware, networking, and security policies. Unlike public or hybrid models, the organization retains exclusive administrative access and can enforce strict compliance requirements without sharing underlying physical resources with other tenants.

Answer

Public cloud

Answer

Hybrid cloud

Answer

Community cloud

Question 9

A company migrates its database to Azure SQL Database (PaaS). According to the shared responsibility model, which of the following is the customer's responsibility?

Accepted Answer

Managing user access and authentication. In the shared responsibility model for Azure SQL Database (PaaS), the customer is responsible for managing user access and authentication because the customer controls who can connect to the database and what permissions they have. Microsoft manages the underlying infrastructure, including the operating system, physical hardware, and virtualization layer, while the customer must secure data access through Azure Active Directory or SQL authentication, configure firewall rules, and manage logins and users.

Answer

Patching the operating system of the database server

Answer

Maintaining the physical infrastructure

Answer

Managing the virtualization layer

Question 10

A cloud provider offers virtual machines, but customers must install, configure, and maintain the operating system and applications. Which cloud service model does this describe?

Accepted Answer

IaaS (Infrastructure as a Service). This scenario describes Infrastructure as a Service (IaaS), where the cloud provider supplies virtualized computing resources such as virtual machines, storage, and networking, but the customer retains full control over the operating system, middleware, and applications. In IaaS, the provider manages only the physical infrastructure (hypervisor, servers, storage, and network), while the customer is responsible for OS installation, configuration, patching, and application management. This aligns directly with the question's description of customer-managed OS and applications on provider-hosted VMs.

Answer

PaaS (Platform as a Service)

Answer

SaaS (Software as a Service)

Answer

FaaS (Function as a Service)

Question 11

A company migrates its database to a cloud service where the provider manages the database engine, patching, backups, and replication. The customer only manages the data and schema. Which cloud service model is this?

Accepted Answer

Platform as a Service (PaaS). Platform as a Service (PaaS) provides a managed hosting environment where the cloud provider handles the underlying infrastructure, including the database engine, operating system, patching, backups, and replication. The customer is responsible only for managing the data and schema, which aligns directly with the scenario described.

Answer

Infrastructure as a Service (IaaS)

Answer

Software as a Service (SaaS)

Answer

On-premises

Question 12

A company wants to run a workload that requires the highest level of physical security and control over hardware. They have the budget to purchase and maintain their own data center. Which cloud deployment model should they choose?

Accepted Answer

Private cloud. A private cloud deployment model is correct because it provides dedicated infrastructure for a single organization, offering the highest level of physical security and full control over hardware. This model allows the company to purchase, own, and manage its own data center, ensuring compliance with stringent security requirements and complete hardware isolation.

Answer

Public cloud

Answer

Hybrid cloud

Answer

Community cloud

Question 13

A company runs a virtual machine in Azure that hosts a web application. The company is responsible for configuring the operating system, installing web server software, and managing application updates. The cloud provider is responsible for the physical hardware, networking, and data center security. Which cloud service model does this represent?

Accepted Answer

Infrastructure as a Service (IaaS). This scenario describes Infrastructure as a Service (IaaS) because the customer manages the operating system, web server software, and application updates, while the cloud provider handles the physical hardware, networking, and data center security. In IaaS, the provider offers virtualized computing resources over the internet, and the customer retains control over the guest OS and installed software, which matches the responsibilities outlined.

Answer

Software as a Service (SaaS)

Answer

Platform as a Service (PaaS)

Answer

Function as a Service (FaaS)

Question 14

A company uses a cloud service that provides virtual machines. The company manages the operating system, middleware, and applications, while the cloud provider manages the physical hardware, networking, and data center security. Which cloud service model does this represent?

Accepted Answer

Infrastructure as a Service (IaaS). This scenario describes Infrastructure as a Service (IaaS) because the customer manages the operating system, middleware, and applications, while the cloud provider is responsible for the physical hardware, networking, and data center security. In IaaS, the provider delivers virtualized computing resources over the internet, and the customer retains control over the guest OS, storage, and deployed applications, which matches the division of responsibilities given.

Answer

Platform as a Service (PaaS)

Answer

Software as a Service (SaaS)

Answer

Desktop as a Service (DaaS)

Question 15

A company wants to run a critical application that requires dedicated hardware to comply with regulatory isolation requirements. However, they want to avoid the upfront cost of building their own data center. Which cloud deployment model meets these needs?

Accepted Answer

Private cloud. A private cloud is the correct deployment model because it provides dedicated hardware and infrastructure for a single organization, ensuring regulatory isolation without requiring the company to build and maintain its own on-premises data center. In Azure, a private cloud can be implemented via Azure Stack Hub or Azure VMware Solution, which run in the customer's own environment or a dedicated hosted environment, meeting compliance needs while avoiding upfront capital expenditure.

Answer

Public cloud

Answer

Hybrid cloud

Answer

Community cloud