Mobile App Design Technology & Digital Applications 3 — Questions and Answers
Question 1: Which rendering approach draws UI components directly on a canvas, bypassing native OS widgets, as used by Flutter?
- Native rendering
- Web-view rendering
- Custom/canvas rendering (Correct answer)
- Server-side rendering
Correct answer: Custom/canvas rendering
Flutter uses its own Skia/Impeller rendering engine to draw all UI widgets to a canvas, ensuring pixel-perfect consistency across platforms.
Question 2: In RESTful API design for mobile, what HTTP status code indicates a successfully created resource?
- 200 OK
- 204 No Content
- 201 Created (Correct answer)
- 301 Moved Permanently
Correct answer: 201 Created
HTTP 201 Created is the correct response when a POST request successfully creates a new resource on the server.
Question 3: What is 'token refresh' used for in mobile OAuth 2.0 authentication flows?
- Re-downloading the app UI theme
- Obtaining a new access token without requiring the user to log in again (Correct answer)
- Resetting the device push notification token
- Refreshing cached API response data
Correct answer: Obtaining a new access token without requiring the user to log in again
A refresh token allows the app to silently obtain a new short-lived access token when the current one expires, maintaining session continuity.
Question 4: Which mobile performance metric measures the time from user interaction to the next frame being painted?
- Time to First Byte (TTFB)
- Frame rate (FPS)
- Input latency / touch response time (Correct answer)
- App cold start time
Correct answer: Input latency / touch response time
Input latency measures how quickly the app visually responds to user touches or gestures, with targets typically under 100ms for a smooth feel.
Question 5: What distinguishes a progressive web app (PWA) from a native mobile app?
- PWAs are faster than all native apps
- PWAs run in a browser engine and can be installed without an app store (Correct answer)
- PWAs have full access to all device hardware APIs
- PWAs require a paid developer account to distribute
Correct answer: PWAs run in a browser engine and can be installed without an app store
PWAs use web technologies and run via the browser engine; they can be added to the home screen but have more limited hardware access than native apps.
Question 6: In mobile app design, what is 'state management' primarily responsible for?
- Managing geographic location permissions
- Controlling and synchronizing application data and UI state across components (Correct answer)
- Handling background app state on iOS
- Managing OS-level power states
Correct answer: Controlling and synchronizing application data and UI state across components
State management ensures that application data is consistently shared and updated across UI components as user interactions and data changes occur.
Question 7: Which GraphQL operation type is used to fetch data from a server?
- Mutation
- Subscription
- Query (Correct answer)
- Fragment
Correct answer: Query
In GraphQL, a Query is used to read or fetch data, while Mutations modify data and Subscriptions listen for real-time updates.
Mobile App Design Technology & Digital Applications 3
Which rendering approach draws UI components directly on a canvas, bypassing native OS widgets, as used by Flutter?