Explanation: EDUSAT (Education Satellite) was launched by the Indian Space Research Organisation (ISRO) in September 2004. It was the first Indian satellite built exclusively for educational purposes, designed to provide distance learning and interactive education through satellite communication.

Explanation: ELISA stands for Enzyme-linked immunosorbent assay. It is a biochemical test used to detect and measure antibodies, antigens, proteins, or hormones in a sample. The method relies on an enzyme-linked antigen or antibody and a color change to indicate a positive reaction.

Explanation: Angora wool is obtained from the Angora rabbit, a special breed reared mainly for its soft, silky, and warm fur. The wool fibers are extremely fine and have a high insulating property, making them ideal for luxury clothing. It is different from Mohair (from Angora goat) and Cashmere (from Kashmiri goat).

Explanation: The full form of GPS is Global Positioning System. It is a satellite-based navigation system that provides accurate information about the location, speed, and time anywhere on Earth. Developed by the U.S. Department of Defense, GPS uses a network of at least 24 satellites orbiting the Earth. It is widely used in navigation, mapping, military operations, aviation, and smartphone tracking applications.

Explanation: In a healthy adult, the total volume of blood in the body is approximately 7% of body weight. For an average person weighing around 70 kg, this equals about 5 to 5.5 litres of blood. Blood plays a vital role in transporting oxygen, nutrients, hormones, and waste products throughout the body. It also helps regulate temperature and maintain pH balance. The major components of blood are plasma (55%), red blood cells (RBCs), white blood cells (WBCs), and platelets.

The Moon takes about 27.3 days to complete one revolution around the Earth with respect to the stars (called the sidereal month). However, due to the simultaneous movement of the Earth around the Sun, the Moon takes approximately 29.5 days to complete one full cycle of phases (from new moon to new moon), known as the synodic month. This period is commonly rounded to 28 days in general usage.

Other options (for context)

• 45 days: Much longer than the Moon’s actual orbital period.
• 50 days: Incorrect — the Moon completes more than one revolution in this time.
• 65 days: Far too long compared to the real lunar cycle.

Explanation: An F1 (Formula One) car is primarily made of carbon fibre, a lightweight yet extremely strong and durable material. Carbon fibre provides high strength-to-weight ratio, excellent rigidity, and improved safety — essential for achieving high speeds and ensuring driver protection in racing conditions.

Explanation: SONAR (Sound Navigation and Ranging) is a system used in ships and submarines to determine the depth of the ocean or to locate underwater objects. It works by sending sound waves into the water and measuring the time taken for the echo to return after reflecting from the seabed or any object.