NCERT CLASS 11 PHYSICS CHAPTER 12 – KINETIC THEORY IN-TEXT / CONCEPT-BASED QUESTIONS AND ANSWERS 1. What is kinetic theory of gases? Answer: Kinetic theory of gases explains the behaviour of gases on the basis of the motion of their molecules. According to this theory, a gas consists of a large number of tiny molecules that are in continuous random motion. The pressure and temperature of a gas are explained in terms of the motion and kinetic energy of its molecules. 2. What is meant by the molecular nature of matter? Answer: The molecular nature of matter means that all substances are made up of extremely small particles called atoms and molecules. These particles are always in motion and have spaces between them. 3. State Avogadro's law. Answer: Avogadro's law states that equal volumes of all gases, at the same temperature and pressure, contain equal numbers of molecules. Mathematically, V ∝ n where V is volume and n is the number of moles. 4. What is an ideal gas? Answer: A...

  NCERT CLASS 11 PHYSICS CHAPTER 13 – OSCILLATIONS IN-TEXT / CONCEPT-BASED QUESTIONS AND ANSWERS 1. What is periodic motion? Answer: Periodic motion is a type of motion in which an object repeats its motion after equal intervals of time. The time taken to complete one cycle is called the time period. Examples: Motion of the Earth around the Sun. Motion of the hands of a clock. Oscillation of a simple pendulum. 2. What is oscillatory motion? Answer: Oscillatory motion is the repeated to-and-fro motion of an object about its mean or equilibrium position. Examples: Motion of a simple pendulum. Motion of a mass attached to a spring. Vibrations of a tuning fork. 3. Differentiate between periodic motion and oscillatory motion. Answer: Periodic motion: Motion that repeats itself after equal intervals of time. It may be circular, rotational or oscillatory. Example: Revolution of the Earth around the Sun. Oscillatory motion: Motion in which an object moves repeatedly to and fro about a mean...