K
 Kilogram: The Kilogram is the usual scientific unit of mass. The standard Kilogram is the mass of a particular cylinder of platinum iridium alloy kept near Paris in France. All masses that are measured are compared with this. Kirchhoff’s first Law: It states that at any junction of several circuit elements, the sum of currents entering the junction must be equal to sum of currents leaving it. Kirchhoff’s second Law: The algebraic sum of charges in potential around any closed resistor loop must be zero. Kelvin’s Thermodynamic Scale: The ratio of two temperatures measured on absolute scale is equal to the ratio of heat absorbed to the heat rejected by a reversible engine working between these temperatures. Kirchoff’s law (thermal radiation): The ratio of emissive power to the absorption power is same for all bodies at a certain temperature for a certain wavelength and it is equal to emissive power of a perfectly black body at that temperature and that wavelength. Kilowatt hour (KWH): It is the unit of electrical energy. 1KWH=36 x 105 Joules. Kepler’s first law: Every planet revolves round the sun in an elliptical orbit with the sun at one of its foci. This law is known as law of orbits. Kepler’s second law: The radius vector joining a planet to the sun sweeps equal areas in equal intervals of time. (or)The areal velocity of a planet round the sun is constant. This law is known as “law of areas”. Kepler’s third law: Square of the time period of revolution of a planet round the sun is directly proportional to the cube of mean distance of the planet from the sun. Kelvin’s statement of second law of thermodynamics: It is impossible to get a continuous supply of work by cooling a body to a temperature lower than that of coldest of its surroundings. Kilo Calorie: The amount of energy required top increase the temperature of one kilogram of water by 1oC.