ICSE Class 7 Physics, Unit 5: Heat

What this unit aims at

Heat is a form of energy. Sunlight carries heat that gives warmth when exposed to it. When water is heated, its energy in the form of heat increases and becomes hot. When heat energy of an object increases, it can result in (i) change of temperature, (ii) change in size and/or (iii) change in state of an object. Some materials like aluminium are good conductors of heat and some, like wood are bad conductors of heat. Heat from a hot object is transferred to a cold object in three different ways- conduction, convection and radiation. Previous learning included topics on temperature and its measurement in degree Celsius. Further, two other frequently used temperature scales, Fahrenheit scale and Kelvin scale have been introduced in this theme for a better understanding of concepts related to temperature.

Your child should be able to

• define heat as energy
• define units of heat
• describe temperature scales: degree Celsius, Fahrenheit and Kelvin
• describe different effects of heat
• explain different modes of heat transfer
• decide about conductor and insulator of heat in different applications
• describe construction and working of thermos flask

Key concepts in this unit

• Heat as a form of energy and its units, joule(J) and calorie (cal).
• Different units of Temperature (°C, °F, K).
• Effects of Heat:
• Change in Temperature.
• Change in Size (Expansion and contraction).
• Change in State.
• Good Conductors and Bad Conductors of Heat and their examples.
• Choice of conductors and insulators in day to day life (Pan handles, metal cooking utensils etc.)
• Methods of Heat Transfer:
• Conduction Convection Radiation Thermos Flask:
• (Application of Heat Transfer)
• Construction Working