science & technology Online Quiz - 223

The first Earth Day was celebrated on April 22, 1970. The Unix epoch date 25648 days corresponds to this date (April 22, 1970). This environmental event launched the modern environmental movement and is now observed annually worldwide.

Yellowstone National Park, established in 1872, was the world's first national park located in the United States. It set the precedent for the global national park movement. Other options are significant parks but were established later - Corbett (1936), Kruger (1898), and Ordesa (1918).

Oranges are most famous for being rich in Vitamin C, which is essential for immune function, collagen synthesis, and antioxidant protection. One medium orange can provide over 100% of the daily recommended intake of Vitamin C.

The kidneys are the primary organs responsible for filtering blood in the human body. They remove waste products, excess substances, and toxins from the blood to produce urine, while also maintaining electrolyte balance and blood pressure regulation.

One foot is exactly equal to 12 inches in the Imperial and US customary measurement systems. This standard has been used for centuries and is fundamental to length measurements in countries that still use these systems.

DVD stands for Digital Versatile Disc (originally Digital Video Disc). It was developed as a digital optical disc storage format that could store higher capacity data than CDs and was primarily used for video but also for data storage, hence the name 'versatile'.

The saffron (kesaria) color at the top of the Indian flag represents sacrifice and strength. It symbolizes the renunciation and selfless dedication of those who fought for India's independence. The white band represents peace and truth, while green stands for prosperity and fertility of the land.

SMS stands for Short Message Service, which is a standard text messaging service component of mobile telephone systems. It allows users to send short text messages (typically 160 characters) between mobile devices. The service was first used commercially in 1992 and has become a ubiquitous communication method worldwide.

The sun appears to rise from the east because Earth rotates on its axis from west to east (counter-clockwise when viewed from above the North Pole). This rotation creates the illusion that the sun moves across the sky from east to west. This fundamental astronomical principle applies everywhere on Earth.

In India, dialing 100 connects you to the police emergency service. This is a universal emergency number across the country for immediate police assistance in criminal matters, emergencies, or law enforcement situations. Other important emergency numbers include 101 for fire and 108 for ambulance/medical services in many states.

Under normal atmospheric pressure (1 atm), pure water freezes at 0 degrees Celsius (32 degrees Fahrenheit). This is the standard freezing point used in most scientific and everyday contexts. -72°C and -100°C are extremely cold, while 100°C is actually the boiling point of water.

A right angle is exactly 90 degrees, which is one-quarter of a full 360-degree rotation. It's the angle formed when two lines are perpendicular to each other. 45° is half of a right angle, 180° is a straight line, and 360° is a complete rotation.

Leap years have 366 days instead of the usual 365 because they include an extra day (February 29th). This extra day compensates for the fact that a solar year is approximately 365.25 days long. A regular year has 365 days, and 360/380 days are not correct.

CCleaner is the most widely used free PC cleaning software that includes registry error fixing capabilities. Developed by Piriform and first released in 2003, it is known for cleaning temporary files, browser caches, and fixing registry issues. Note that 'famaous' in the question is a typo for 'famous'.

Deep Burner Free is a legitimate free CD/DVD burning software. Nero is primarily a commercial paid product. Ashampoo Burning Studio is also mainly a commercial product. Deep Burner stands out as one of the genuinely free options among these choices.

Open Office (Apache OpenOffice) is a well-known free and open-source office suite that provides alternatives to Microsoft Office applications like Word, Excel, and PowerPoint. It can read and write MS Office formats. DOS-Office and Free-Office are not recognized alternatives, while 'None' is incorrect.

Google Chrome has consistently ranked among the fastest browsers in benchmarks due to its V8 JavaScript engine and efficient rendering. However, browser performance varies by test methodology, version, and system - 'latest ratings' is temporally vague.

Skype is a free VoIP application that enables voice and video calls between computers over the internet. The other options (Hype, PC Caller, Nod32) are not PC-to-PC communication tools - Nod32 is antivirus software.

Comodo Firewall is a well-known free firewall software for Windows. Zone Alarm Pro is a paid commercial product (though a free version exists), while Hit-Fire and Threat fire are not recognized firewall products.