Balancing a chemical equation ensures that the Law of Conservation of Mass is followed, meaning the number of atoms of each element must be the same on both the reactant and product sides of the equation. To systematically balance a chemical equation, follow these steps: Step-by-Step Method to Balance Chemical Equations Example 1: Combustion of … Read more

Q 1. Find the distance of point (–12, 5) from the origin. Ans: 13 Q 2. Find the value of a if the distance between (a, 3) cm and (–2, 6) cm is 5 cm. Ans: -6 or 2 Q 3. The two shorter sides of a right-angled triangle are 5 cm and 12 cm. Let θ … Read more

1. The magnitude of any physical quantity: Answer: 1 2. What is the unit of measurement of solid angle? Answer: 1 3. Newton-second is the unit of Answer: 3 4. Which of the following is not the unit of energy. Answer: 4 5. Candela is the unit of: Answer: 2 6. Universal time is based on: Answer: 3 7. Which of … Read more

Measurement of Length: 1. Distance between two cities, in standard units will be measured in ______a) Meterb) Kilometerc) Miled) Centimeter Answer: aExplanation: The standard unit of measurement is meter; hence the answer is meter. The distance between two cities is usually measured in kilometer but the standard unit is meter. 2. Which of the following … Read more

1. The number of base units for measuring physical quantities according to the SI system are ____a) 1b) 10c) 7d) 8 Answer: cExplanation: There are 7 base units for measuring physical quantities according to the SI system. They are kilogram (kg) for mass, second (s) for time, kelvin (K) for temperature, ampere (A) for electric … Read more

1. The pair of quantities having the same dimensions is (a) displacement, velocity (b) time, frequency (c) wavelength, focal length (d) force, acceleration Answer:(c) wavelength, focal length 2. Average distance of the Sun from the Earth (a) light year (b) astronomical unit (c) fermi (d) parsec Answer: (b) astronomical unit 3. The number of significant … Read more

MCQ-6 This set of Class 12 Physics Chapter 14 Multiple Choice Questions & Answers (MCQs) focuses on “Semiconductor Electronics – Application of Junction Diode as a Rectifier”. 1. What is a rectifier used for?a) Convert ac voltage to dc voltageb) Convert dc voltage to ac voltagec) Measure resistanced) Measure current Answer: aExplanation: A rectifier is … Read more

MCQ-5 This set of Class 12 Physics Chapter 14 Multiple Choice Questions & Answers (MCQs) focuses on “Semiconductor Diode”. 1. Why is there a sudden increase in current in Zener diode?a) Due to the rupture of ionic bondsb) Due to rupture of covalent bondsc) Due to viscosityd) Due to potential difference Answer: bExplanation: The sudden … Read more