Correct: D. Android

Android (by Google) and iOS (by Apple) are the two major mobile operating systems that dominate the global market. Android is an open-source system used by many different phone makers (Samsung, Pixel, etc.), while iOS is a closed system used exclusively on the iPhone and iPad.

Correct: D. Application Programming Interface

API stands for Application Programming Interface, which is a set of rules that allow two different pieces of software to communicate with each other. For example, when you see a "Google Maps" window inside a restaurant's website, that website is using an API to "ask" Google's servers for the map data.

Correct: D. Graphical User Interface

GUI stands for Graphical User Interface. It allows users to interact with electronic devices through visual indicators like icons, menus, and windows, instead of having to type text-based commands into a terminal.

Correct: A. Sputnik 1

Sputnik 1 was the first artificial satellite to orbit the Earth, launched by the Soviet Union on October 4, 1957. It was a metal sphere with four antennas that transmitted a "beep-beep" radio signal back to Earth.

Correct: B. Megabits per second

Mbps stands for Megabits per second. It is the unit of measurement used to describe the speed of an internet connection (the rate at which data is transferred).

Correct: B. NFC

NFC (Near Field Communication) is the wireless standard used for very short-range data exchange, typically within 4 centimeters. It is the technology behind "Tap to Pay" systems like Apple Pay and Google Pay, as well as digital transit cards.

Correct: C. Ada Lovelace

Ada Lovelace is widely considered the first computer programmer. In the 1840s, while working with Charles Babbage on his proposed "Analytical Engine," she wrote an algorithm intended to be processed by the machine. She was the first to realize that computers could do more than just math.

Correct: D. The core part that manages hardware

The Kernel is the core part of an operating system. It acts as a bridge between applications and the actual data processing performed at the hardware level. It manages the CPU, memory, and devices.

Correct: A. Tim Berners-Lee

Sir Tim Berners-Lee, the inventor of the World Wide Web, founded the World Wide Web Consortium (W3C) in 1994. The organization's goal is to lead the web to its full potential by developing protocols and guidelines (like HTML and CSS standards) that ensure long-term growth for the web.

Correct: D. White Hat

A White Hat hacker is an ethical hacker who uses their skills to find security vulnerabilities in systems so they can be fixed before "bad" hackers (Black Hats) find them. Many companies pay "Bug Bounties" to white hat hackers for finding flaws.

Correct: A. Subscriber Identity Module

SIM stands for Subscriber Identity Module. It is an integrated circuit that is intended to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices.

Correct: B. Computer Generated Imagery

CGI stands for Computer-Generated Imagery. It refers to the use of computer graphics to create or enhance images in art, printed media, video games, films, and television programs.

Correct: B. Martin Cooper

Martin Cooper made the historic first call on April 3, 1973, using a prototype Motorola DynaTAC 8000X while walking on a New York City street. He famously called his rival, Joel Engel at Bell Labs, to inform him that he was speaking from a 'real, handheld, portable cell phone.' This event marked the beginning of the end for wired telephony and the rise of the mobile era.

Correct: C. Millimeter Wave (mmWave)

mmWave is the ultra-high frequency part of the 5G spectrum that provides the 'gigabit' speeds often touted in marketing. While it offers massive bandwidth, the signals are easily blocked by walls, windows, and even rain, requiring a dense network of 'small cells' in urban areas. Most 5G coverage today actually uses 'Sub-6' frequencies, which travel further but offer lower peak speeds.

Correct: C. Four

While three satellites can provide a 2D position (latitude and longitude), a fourth satellite is required to calculate altitude and correct for time errors in the receiver's clock. This process is called trilateration, where the receiver measures the time it takes for signals to arrive from each satellite. The more satellites a receiver can 'see,' the more accurate the resulting location data will be.

Correct: C. LED monitors require a backlight, while OLED pixels produce their own light

In a standard LED monitor (which is actually an LED-backlit LCD), a panel of lights shines through a layer of liquid crystals to create images. In an OLED (Organic Light Emitting Diode) display, every individual pixel is its own light source, allowing it to turn off completely for perfect black levels. This results in superior contrast and faster response times, though OLEDs are more susceptible to image 'burn-in.'

Correct: C. 1940s

The transistor was invented in December 1947 by John Bardeen, Walter Brattain, and William Shockley at Bell Labs. It replaced the bulky, fragile, and inefficient vacuum tubes used in early computers and radios, allowing for the miniaturization of electronics. The three inventors were awarded the Nobel Prize in Physics in 1956 for this monumental achievement.

Correct: B. Xerox PARC

Xerox PARC (Palo Alto Research Center) developed the Xerox Alto in 1973, which featured the first true GUI with windows, menus, and a mouse. Steve Jobs famously visited PARC in 1979 and was so impressed that he integrated these concepts into the Apple Lisa and later the Macintosh. While Xerox failed to commercialize the technology effectively, it set the standard for all modern computing interfaces.

Correct: C. Mainframe

Mainframes are distinct from supercomputers; while supercomputers focus on raw calculation speed for science, mainframes focus on transaction reliability and massive input/output. They are famous for their 'five nines' availability (99.999% uptime) and can handle thousands of simultaneous users and transactions without failing. Many banks and airlines still rely on IBM Z-series mainframes for their core operations today.

Correct: C. Pulse Oximeter

A pulse oximeter works by shining red and infrared light through the skin and measuring how much of each wavelength is absorbed by the blood. Oxygenated blood absorbs more infrared light, while deoxygenated blood absorbs more red light. This technology became a high-profile feature in wearables like the Apple Watch and Garmin devices during the COVID-19 pandemic.

Correct: A. Zigbee

Zigbee is designed to be a simpler and less expensive alternative to other wireless personal area networks (WPANs) like Bluetooth or Wi-Fi. It uses a 'mesh' architecture, where each device can pass data to others, extending the range of the network across a whole house. Because it uses very little power, Zigbee sensors can often run on a single coin-cell battery for years.

Correct: B. An offline storage device used to keep private keys secure from online hackers

A cold wallet, such as a hardware device like Ledger or Trezor, keeps the user's private keys entirely offline, making them immune to remote hacking attempts. This is contrasted with 'hot wallets' which are connected to the internet and are more convenient for frequent trading but more vulnerable to theft. Cold storage is widely considered the gold standard for long-term security of significan't crypto holdings.

Correct: C. Blue-Violet Laser

Blu-ray uses a blue-violet laser with a shorter wavelength (405nm) than the red laser (650nm) used in standard DVDs. This shorter wavelength allows the laser to focus on smaller pits of data, enabling a single Blu-ray disc to store up to 50GB of data, compared to a DVD's 4.7GB. This increased capacity was essential for the transition to High Definition (HD) and 4K video content.

Correct: A. Douglas Engelbart

Douglas Engelbart's 1968 presentation introduced not only the mouse but also hypertext, video conferencing, and word processing, predicting the future of computing decades in advance. The original mouse was a wooden block with two metal wheels and a single button. While revolutionary, it took nearly 15 years to become a standard commercial product with the Apple Lisa and Macintosh.

Correct: A. Iris Recognition

Iris recognition uses the unique, complex patterns in the iris (the colored part of the eye), which remain stable throughout a person's life and are nearly impossible to replicate. Unlike fingerprints, which can be 'lifted' or altered by cuts and scrapes, the iris is protected by the cornea and contains significan'tly more unique data points for comparison. High-security facilities and some national ID programs use iris scans for rapid, highly accurate identification.

Correct: C. FLOPS (Floating Point Operations Per Second)

FLOPS is a measure of a computer's performance, specifically its ability to perform mathematical calculations involving decimal points. While a standard PC might reach gigaflops or teraflops, modern supercomputers have entered the 'Exascale' era, performing over a quintillion (one billion billion) calculations per second. This power is used for complex tasks like weather forecasting, nuclear simulation, and drug discovery.

Correct: B. The sensitivity of the image sensor to light

ISO is a carryover from the film era, where it represented the light sensitivity of the physical film; in digital cameras, it refers to the amplification of the signal from the sensor. A higher ISO allows you to take photos in darker environments without a flash, but it introduces 'digital noise' or graininess to the image. Modern high-end cameras have improved drastically, allowing for clean images at ISO levels that were impossible just a decade ago.

Correct: A. 2.4 GHz

The 2.4 GHz band has a longer wavelength, allowing it to penetrate solid objects like walls and floors more effectively than higher frequencies. However, it is a very 'crowded' band used by microwaves, baby monitors, and older Bluetooth devices, which leads to significan't interference. In contrast, the 5 GHz and 6 GHz bands offer much faster speeds and less congestion but have a much shorter range.

Correct: C. Thunderbolt

Thunderbolt was co-developed by Intel and Apple to provide a single cable solution for high-speed data, video output, and power. It effectively brings the speed of the computer's internal PCIe bus to external peripherals, allowing for 'External GPUs' and ultra-fast storage arrays. The latest versions (Thunderbolt 4 and 5) use the USB-C connector but offer much higher guaranteed minimum speeds than standard USB.