Tag: science & technology

Galileo discovered Ganymede in 1610, making option B correct. Ganymede is Jupiter's largest moon. The Moon, Titan (Saturn's moon), and Pluto are not correct.

Titan is the largest moon of Saturn, discovered by Christiaan Huygens in 1655. Option B is a company name, Mars and Jupiter are planets not moons.

The question appears to ask for the SI unit of luminous intensity, which is the candela (option B). Lumex is not a standard SI unit.

The calorie is a unit of energy, specifically the amount of heat needed to raise 1 kg of water by 1°C. Joule is also an energy unit, Newton measures force, and Lumex is not a standard unit.

The decibel is the logarithmic unit used to measure sound intensity levels. Hertz measures frequency, Newton measures force, and Tesla measures magnetic field strength.

Only about 3% of Earth's total water is freshwater, with the vast majority (approximately 97%) being saltwater in oceans and seas. Of that small freshwater portion, most is locked in glaciers, ice caps, and groundwater, leaving less than 1% as accessible surface freshwater.