Microsoft Azure Fundamentals (AZ-900) — All Questions

A company wants compute capacity to automatically increase during busy periods and decrease when demand falls, without manual intervention. Which cloud characteristic is this?

• a.High availability
• b.Data residency
• c.Elasticity✓
• d.Disaster recovery

Elasticity is the automatic adding and removing of resources to match demand in real time. High availability keeps services running despite failures, disaster recovery restores service after an outage, and data residency concerns where data is stored geographically.

Moving from buying on-premises servers to paying monthly for cloud resources based on usage represents which shift?

• a.From private to public data residency
• b.From capital expenditure (CapEx) to operating expenditure (OpEx)✓
• c.From OpEx to CapEx
• d.From SaaS to IaaS

Buying hardware upfront is a capital expenditure, while pay-as-you-go cloud consumption is an operating expenditure, so the move is CapEx to OpEx. The other options reverse the direction or describe unrelated concepts.

Under the shared responsibility model, which task is always the customer's responsibility regardless of the service model?

• a.Securing the physical datacenter
• b.Replacing failed disks
• c.Maintaining the host hypervisor
• d.Managing its own data and user access✓

The customer is always responsible for its data, identities, and access management no matter the model. Physical security, the hypervisor, and hardware maintenance are always Microsoft's responsibility.

A team wants to run applications without managing the underlying operating system, servers, or patching, but still deploy custom code. Which service model fits best?

• a.Platform as a Service (PaaS)✓
• b.On-premises
• c.Software as a Service (SaaS)
• d.Infrastructure as a Service (IaaS)

PaaS provides a managed platform where you deploy your own application code while Microsoft handles the OS, servers, and patching. IaaS still requires you to manage the OS, SaaS delivers finished applications with no custom code, and on-premises means you manage everything.

An organization keeps sensitive records in its own datacenter but bursts to Azure for extra capacity at peak times, connecting the two. Which deployment model is this?

• a.Private cloud
• b.Community cloud
• c.Hybrid cloud✓
• d.Public cloud

A hybrid cloud connects a private environment with the public cloud so workloads and data can move between them. A pure public or private cloud uses only one environment, and community cloud is shared among organizations with common concerns.

Which pair correctly distinguishes scalability from elasticity?

• a.They are identical terms
• b.Elasticity only applies to storage
• c.Scalability is automatic; elasticity is manual
• d.Scalability adds capacity as planned; elasticity adds and removes it automatically with demand✓

Scalability is the ability to increase capacity (often planned or manual), whereas elasticity automatically scales resources up and down in response to real-time demand. They are not identical, the roles are not reversed, and elasticity is not limited to storage.