Mobile App Design Technology & Digital Applications 4

Question 1

What is the purpose of code signing in iOS app distribution?

Accepted Answer

Verifying the app's identity and ensuring it hasn't been tampered with

Answer

Code signing uses certificates from Apple to cryptographically prove the app's origin and ensure its binary integrity since signing.

Question 2

Which background execution mode allows an iOS app to periodically fetch content even when not in use?

Accepted Answer

Background App Refresh

Answer

Background App Refresh lets iOS periodically wake the app to download new content, with iOS controlling the actual frequency based on usage patterns.

Question 3

In mobile networking, what does 'exponential backoff' describe?

Accepted Answer

Increasingly longer wait times between retry attempts after failures

Answer

Exponential backoff doubles the wait time between each successive retry attempt, preventing overwhelming a struggling server while still eventually retrying.

Question 4

What is the main advantage of using vector graphics (SVG/PDF) over raster images (PNG) in mobile UI?

Accepted Answer

Crisp rendering at any screen size or density without additional assets

Answer

Vector graphics scale mathematically and remain sharp at any resolution, eliminating the need to provide @1x, @2x, and @3x raster variants.

Question 5

Which security practice involves validating data both on the client and the server side in a mobile app?

Accepted Answer

Defense in depth / dual-layer validation

Answer

Dual-layer validation ensures that even if client-side validation is bypassed, the server still enforces rules, protecting against malicious requests.

Mobile App Design Practice Test

Mobile App Design Practice Test

Mobile App Design Technology & Digital Applications 4