Science & Technology Fundamentals

Windows stores device driver settings and most system configuration in the Registry, a hierarchical database. BIOS contains firmware settings, CMOS stores BIOS/UEFI configuration data, and EEPROM is a type of memory chip. The Registry holds hardware profiles, driver parameters, and system settings that Windows uses to load and configure drivers at boot.

All three power line issues can damage computers. Line sag (undervoltage) can cause system instability and data corruption, line surge (overvoltage/spikes) can fry components, and line noise (EMI/RFI) introduces signal errors that corrupt data transfer. Power protection devices like UPS and surge protectors mitigate these problems.

In gear mechanics, the gear with fewer teeth has smaller individual teeth that are weaker in bending strength. Since both gears are made of the same material, the 20-tooth gear has smaller, weaker teeth compared to the 40-tooth gear. The 40-tooth gear has more teeth distributing the load, making it stronger. Load distribution depends on tooth size and number.

In the formula for the critical angle, n1 represents the refractive index of the less dense medium (usually air) and n2 represents the more dense medium. Total internal reflection occurs when light travels from n2 to n1.

Halogens (Group 17 elements) have 7 electrons in their outermost shell. This is one electron short of a stable octet, explaining their high reactivity. Fluorine, chlorine, bromine, and iodine all follow this pattern.

Blood group AB individuals have both A and B antigens on their RBCs, so they don't produce anti-A or anti-B antibodies. This makes them universal recipients. Option A correctly states this, though they can receive from A, B, AB, and O donors, not just A and B.

To find the bending load on a gear tooth: Power = 2 KW, Speed = 1000 RPM, PCD = 200 mm. First, calculate torque: Torque = Power / Angular velocity. Angular velocity = (2π × RPM) / 60 = (2π × 1000) / 60 = 100π/3 rad/s. Torque = 2000 W / (100π/3) = 60/π Nm. Tangential force (bending load) = Torque / radius = (60/π) / 0.1 = 600/π N. The answer is 600/π, which matches option C.

SSL (Secure Sockets Layer) is a standard security technology for establishing an encrypted link between a server and a client. The link ensures that all data passed between the web server and browser remains private and integral.

A botnet is a network of compromised computers (zombies) controlled by a malicious actor without the owners' knowledge. The term combines 'robot' and 'network' - these machines are used to send spam, launch DDoS attacks, or other malicious activities.

Compounds form through chemical bonding, which includes all three mechanisms: some elements lose electrons (ionic bonding), some gain electrons (ionic bonding), and some share electrons (covalent bonding). 'All of these' correctly captures that compounds can form via any of these processes.

Ozone (O3) in the stratosphere absorbs UV radiation and traps heat in the atmosphere, making it a greenhouse gas. While CO2 is the most abundant greenhouse gas, the question specifically asks for 'a' heat-trapping gas, and O3 is correct.

The pelagic zone is the open ocean area away from the shore and sea floor, essentially the 'open sea'. It has nothing to do with pelvic anatomy (pelvic girdle), polar regions, or African plains.

Stars are primarily composed of hydrogen (about 74% by mass) and helium (about 24%) through nuclear fusion. While oxygen exists in stars, it's not one of the two primary components.

Pheromones are chemical signals detected through the olfactory system (smell), which is why they trigger instinctive responses. While some animals use taste (the vomeronasal organ), smell is the primary human sense for pheromone detection.

Arachnids are eight-legged arthropods including spiders, scorpions, ticks, and mites. Cockroaches are insects (six legs), making them the correct answer for 'not an arachnid'.

Substances with pH below 7 are acidic because they have a higher concentration of hydrogen ions (H+) than pure water. A base would have a pH above 7, while pH 7 is neutral.

Edwin Hubble provided the first observational evidence that there are galaxies beyond the Milky Way in the 1920s by showing that spiral nebulae were actually distant galaxies, not nearby gas clouds.

Asteroids are rocky objects orbiting the sun that are too small to be considered planets, which is why they're historically called minor planets. They're primarily found in the asteroid belt between Mars and Jupiter.