Refresh facts & stats

Question 1

A 60 Hz display redraws its image how often?

Accepted Answer

60 times per second. Hertz means per second, so a 60 Hz screen refreshes 60 times each second.

Question 2

In many phone apps, which gesture refreshes a feed or list?

Accepted Answer

Pulling down from the top of the list. Pull-to-refresh became a common touchscreen pattern: drag the list down and release to check for new content.

Question 3

What is the traditional frame rate of cinema film with sound?

Accepted Answer

24 frames per second. Sound films standardised on 24 frames per second in the late 1920s, and cinema still widely uses it.

Question 4

What does a 'hard refresh' in a web browser do?

Accepted Answer

Reloads the page while ignoring cached copies. A hard refresh fetches files again from the server instead of using stored cached versions.

Question 5

What is the visual glitch called when a screen shows parts of two different frames at once?

Accepted Answer

Screen tearing. Tearing appears as a horizontal split when new frames arrive out of step with the display's refresh; V-Sync can prevent it.

Question 6

Why does DRAM computer memory need to be refreshed constantly?

Accepted Answer

Its tiny capacitors slowly leak their charge. Dynamic RAM stores each bit as charge in a capacitor, which leaks, so it is rewritten many times a second.

Question 7

Analog PAL television, used across much of Europe, ran at how many frames per second?

Accepted Answer

25. PAL showed 25 frames per second as 50 interlaced fields, matching the 50 Hz mains supply.

Refresh facts & stats

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