Practice MCQs

Explanation: The chemical symbol for gold is Au, derived from the Latin word aurum. Gold's atomic number is 79.

Explanation: Aluminium is the most abundant metal in Earth's crust, making up about 8% of its total mass. It is found mainly as bauxite ore.

Explanation: Common salt (sodium chloride) has the chemical formula NaCl, consisting of one sodium (Na) and one chlorine (Cl) atom held together by an ionic bond.

Explanation: Pure water has a pH of 7, which is neutral. pH below 7 is acidic and above 7 is basic/alkaline.

Explanation: Hydrogen has atomic number 1, meaning it has one proton. It is the lightest and most abundant element in the universe.

Explanation: The SI unit of electric current is the Ampere (A), named after French physicist André-Marie Ampère. It measures the flow of electric charge per unit time.

Explanation: F = ma is Newton's Second Law of Motion. It states that the force on an object equals its mass multiplied by its acceleration.

Explanation: Sound travels at approximately 340 m/s (about 1224 km/h) in air at room temperature (20°C). This speed varies with temperature and medium.

Explanation: Ohm's Law: V = I × R, where V is voltage, I is current and R is resistance. It describes the relationship between these fundamental electrical quantities.

Explanation: The SI unit of force is the Newton (N), named after Sir Isaac Newton. One Newton is the force needed to accelerate a 1 kg mass at 1 m/s².