E-Commerce Development Mobile Commerce 2

Question 1

Which CSS media query breakpoint is most commonly used to target mobile devices with screens up to 768px wide?

Accepted Answer

@media (max-width: 768px)

Answer

max-width: 768px is the standard breakpoint for targeting tablets and mobile devices in responsive design.

Question 2

What is the primary benefit of using a Progressive Web App (PWA) for mobile commerce over a native app?

Accepted Answer

No app store submission required

Answer

PWAs can be installed directly from the browser without going through an app store, lowering the distribution barrier.

Question 3

Which payment method is specifically designed for one-tap checkout on mobile devices by storing card details with the browser?

Accepted Answer

Payment Request API

Answer

The Payment Request API lets browsers surface stored payment credentials for frictionless one-tap checkout.

Question 4

A mobile e-commerce site scores 3.8s on Largest Contentful Paint (LCP). According to Google, this rating is:

Accepted Answer

Needs Improvement

Answer

Google's LCP threshold is Good ≤2.5s, Needs Improvement 2.5–4s, and Poor >4s, so 3.8s falls in Needs Improvement.

Question 5

Which mobile-specific HTML attribute on an <input> field triggers a numeric keypad instead of the full keyboard?

Accepted Answer

inputmode="numeric"

Answer

inputmode="numeric" tells the browser to display a numeric keyboard without restricting input validation.

E-Commerce Development Practice Test