Everyday Science

As of May 2024, the number of countries that have signed NASA's Artemis Accords is 42, according to multiple authoritative sources including NASA and SpacePolicyOnline. The options given were 29, 30, 40, and None of These. Since 42 is not listed among the options, the correct choice is 'None of These'. The previous answer of 30 was an underestimate based on older data. The Artemis Accords have grown rapidly since their inception in 2020, with signatories from all continents.

Severe deficiency of Vitamin D leads to rickets, a condition characterized by softening and weakening of bones in children. Scurvy is caused by Vitamin C deficiency, and night blindness is due to Vitamin A deficiency.

NASA's Perseverance rover successfully landed on Mars in February 2021 as part of the Mars 2020 mission. The other options are either incorrect or not related to NASA rovers.

The ice giants Uranus and Neptune are primarily composed of volatile substances such as water, ammonia, and methane ices, which distinguishes them from gas giants composed mostly of hydrogen and helium.

BTU (British Thermal Unit) is a unit of energy commonly used to measure heat. It represents the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

The Sun completes one full rotation at its equator approximately every 25 days. This is due to the Sun's differential rotation, where the equator rotates faster than the poles.

The Sun's diameter is approximately 109 times that of the Earth, making option C the correct answer. This is a well-established fact in astronomy.

Aluminium, gold, and graphite are all conductors of electricity. Aluminium and gold are metals known for their excellent electrical conductivity, while graphite, a form of carbon, also conducts electricity due to its structure. Therefore, the correct answer is D, as all listed options are conductors.

Uranus was discovered by William Herschel in 1781, making option C the correct answer. The other options are incorrect as they are unrelated to the discovery of Uranus.

The Chandrayaan-3 mission was successfully launched from the Satish Dhawan Space Centre, which is the primary spaceport of ISRO located in Sriharikota, India. This is the correct and official launch site for many of ISRO's missions.