The correct answer is (a) - 2, (b) - 4, (c) - 1, (d) - 3. Explanation & Key Takeaways: • Bernoulli's Principle • It is formulated by Daniel Bernoulli. • It states that "The total mechanical energy of the moving fluid comprising the gravitational potential energy of elevation, the energy associated with the fluid pressure, and the kinetic energy of the fluid motion remains constant". • It can be derived from the principle of conservation of energy. • Due to the shape of an aeroplane's wings, the air passes at a higher speed over the upper surface than the lower surface. • The difference in speed of the air is calculated using this principle. • Buoyant Force • It is the net upward force on an object in any fluid (liquid or gas). • If the buoyant force is greater than the object's weight, then the object will rise above and float. • An Air balloon is a good example. • Newton's Law • Newton's third law of motion states that "For every action, there is always an equal and opposite reaction". • If an object applies force to another, the second object reacts by applying force to the first object. • The two forces exerted by the objects will always have an equal magnitude but reacts in the opposite direction. • Rocket propulsion is a good example. • Law of thermodynamics • The second law of thermodynamics explains the working of the steam engine. • The law states that "Heat flows spontaneously only from hotter to colder bodies". • A steam engine is an example of the second law of thermodynamics.