Analog signals (like sound waves) are continuous. How do computers capture analog audio and convert it to digital?

They sample the wave thousands of times per second and record the amplitude (height) of the wave at each sample as a number They photograph the sound wave and store the image as a JPEG They convert the sound to light pulses and store the light pattern They store the exact mathematical equation of the sound wave

Why is digital data generally more reliable for storage and transmission than analog data?

Digital data uses only 0s and 1s — small errors or noise can be detected and corrected without affecting the result Digital devices are made of better materials that never break down Digital data is stored in a vacuum-sealed format that prevents decay Digital data is always encrypted, so errors can't affect it

A music streaming service claims to offer 'lossless' audio. What does this mean for the listener?

The audio file contains every sample exactly as recorded — no quality was sacrificed during compression The audio streams without any buffering or interruption The audio has no background noise or imperfections from the original recording The audio was recorded in a professional studio without compression

What is a 'checksum' and how is it used to verify file integrity?

A checksum is a number calculated from a file's data — if the file changes even slightly, the checksum changes, revealing corruption or tampering A checksum is the total size of a file in bytes A checksum is a password that protects a file from being opened by others A checksum counts how many times a file has been copied

Why does converting a photo from JPEG to PNG and back to JPEG result in lower quality than the original JPEG?

Each JPEG conversion applies lossy compression again, and losses compound — quality degrades with every re-save PNG files damage JPEG data during conversion due to format incompatibility PNG files automatically shrink images, which is why the JPEG looks worse This only happens on Windows — Mac computers preserve quality during conversion

What information can be found in the EXIF metadata of a photo taken with a smartphone?

GPS location, date and time, camera model, lens settings, and sometimes the phone's serial number Only the image resolution and file size The names of all people who have viewed the photo The app used to edit the photo and the filter applied

A city installs 1,000 traffic sensors collecting data every second. Each reading is 50 bytes. How much data do they collect per day?

About 4.3 GB per day (1,000 sensors × 50 bytes × 86,400 seconds) About 50 MB per day About 50 GB per day About 500 MB per day

What is 'open data' and why do some governments and organizations publish it?

Publicly available datasets that anyone can access, use, and share — governments publish it to increase transparency and enable research Data that has been decrypted and can be read without special software Data stored in open-source file formats only Data collected without any privacy protections or user consent

What is 'big data' and what makes it different from regular data?

Datasets so large and complex that traditional database tools can't handle them — requiring specialized systems to process and analyze Any dataset larger than 1 GB Data collected by large corporations only Data stored on the biggest available hard drives

When you use an incognito/private browsing window, which of these does it actually prevent?

It prevents your browser from saving your history, cookies, and form data on your local device after the session ends It hides your identity completely from websites you visit It encrypts all your internet traffic so no one can see what you're doing It prevents advertisers from tracking you across the internet permanently