Tag: science & technology

Vitamin D deficiency causes rickets, a condition characterized by soft and weak bones primarily in children. In adults, severe deficiency leads to osteomalacia. Vitamin D is essential for calcium absorption and bone mineralization. Rickets presents with bowing of legs, skeletal deformities, and growth retardation.

Eratosthenes, a Greek scholar and chief librarian at Alexandria, calculated Earth's circumference around 240 BCE by measuring the sun's angle at noon on the summer solstice at two locations (Alexandria and Syene). His method was remarkably accurate, yielding a value close to the actual circumference. Hipparchus came later and developed trigonometry.

Vitamin C (ascorbic acid) deficiency causes scurvy, characterized by fatigue, swollen gums, bleeding from mucous membranes, and poor wound healing. Scurvy was historically common among sailors on long voyages without fresh fruit. Vitamin C is essential for collagen synthesis. The other options are unrelated: Haemophilia is a clotting disorder, colour blindness is genetic, and loss of appetite is nonspecific.

All three mathematicians made seminal contributions during India's classical period (400-1200 CE). Aryabhatta (5th century) developed the place-value system and pi approximation; Brahmagupta (7th century) defined zero and negative numbers; Bhaskara II (12th century) wrote on calculus, algebra, and astronomy. This period represents the golden age of Indian mathematics.

A 32-bit CPU can address 2^32 bytes of memory, which equals 4,294,967,296 bytes or exactly 4096 MB (4 GB). This is a fundamental limit of 32-bit architecture. The incorrect options (4024MB, 4000MB, 4128MB) are all close but not the correct mathematical value. This is why 32-bit systems cannot utilize more than 4GB of RAM.

Galileo discovered Ganymede in 1610 using his telescope, making it the first moon discovered orbiting a planet other than Earth. Titan orbits Saturn, Pluto is a dwarf planet, and Earth's moon was known since ancient times.

The Twin Paradox is a famous thought experiment in special relativity where one twin travels at high speed and returns younger than the other. It demonstrates time dilation, not gravitational motion or classical mechanics.

Earth's average orbital speed around the Sun is approximately 29.8 km/s, calculated from Earth's orbital circumference divided by one year. Option B has wrong units, C is a time period, and D is angular speed.