Science

The seasons change because the Earth revolves around the Sun, causing different parts of the Earth to receive varying amounts of sunlight throughout the year. This revolution, combined with the tilt of Earth's axis, results in seasonal changes.

The SI unit of electric current is the ampere, which measures the flow of electric charge per second. Coulomb is the unit of electric charge, and volt is the unit of electric potential difference.

The primary colors in traditional color theory (used in painting and mixing pigments) are red, yellow, and blue. These colors cannot be created by mixing other colors and are used to create other colors.

Einstein's famous equation is E=mc², which expresses the equivalence of mass (m) and energy (E) with c representing the speed of light squared. This shows that mass can be converted into energy and vice versa.

Venus is the brightest planet visible from Earth and is easily seen with the naked eye, often called the 'Evening Star' or 'Morning Star'. Mercury and Mars are visible but not as prominently as Venus.

A biosensor is commonly used to measure blood glucose levels, especially in diabetic patients, by detecting glucose concentration in the blood. While biosensors can be designed for other analytes, the most typical and well-known application is glucose monitoring.

The Earth's atmosphere is composed primarily of nitrogen, which makes up about 78% of the atmosphere by volume. Oxygen is the second most abundant gas, but nitrogen is the principal constituent.

The salinity of seawater is commonly expressed as the amount of dissolved salts in grams per kilogram of seawater. On average, seawater contains about 35 grams of dissolved salts per kilogram, not 1 gram. Sodium chloride (common salt) makes up about 85% of these dissolved salts, so roughly 30 grams of sodium chloride are present per kilogram of seawater. Therefore, the correct amount of common salt in 1 kilogram of seawater is approximately 30 grams, which is not among the options A (1 gram), B (10 grams), or C (1 kg). Hence, the correct answer is D (None of these).

According to the Big Bang Theory, the Universe began about 13.8 billion years ago, which does not fall within any of the ranges provided in options A, B, or C. Therefore, the correct answer is 'None of these'.

Jupiter is commonly known as the 'Bodyguard of the Earth' because its massive gravitational field acts as a cosmic shield, deflecting, capturing, or ejecting many comets and asteroids that might otherwise collide with Earth. While Saturn also has a strong gravitational influence, Jupiter's role in protecting Earth from many potential impacts is more significant and widely recognized in astronomy.