question_answer

DIRECTIONS: Read the passage given below an answer the questions that follow. Passage - 1 Substances that conduct heat very well are called good conductors of heat or thermal conductors. All the metals such as silver, copper, aluminum, iron, mercury and metal alloys such as brass, steel and stainless steel are good conductors of heat. Though all the metals are good conductors of heat, some metals are better conductors of heat than the others. Among metals, silver metal is the best conductor of heat, next is copper and lowest is lead. Substances that do not conduct heat very welfare called bad conductors or poor conductors or insulators of heat. Some of the examples of heat or thermal insulators are plastic, wood, paper, cloth, thermocol, rubber, etc. Liquids like water are poor conductors and gases are very poor conductors of heat. Thus, air is a very good insulator of heat. Which of the following is the best insulator of heat?

A) air               

B) silver

C) iron                             

D) water