Conduction
Question
What do you expect when you put the spoon in a cup of hot tea?
Question
a. Temperature of the spoon stays at 25 degrees celsius
b. Temperature of the spoon will be more than 25 degrees celsius
c. Temperature of the spoon will be less than 25 degrees celsius
The metal spoon is at 25 degrees celsius and it is put in cup of tea which is at 80 degrees celsius. After 2 minutes, touch the top end of the spoon gently. What do you expect?
question
Let's look at the steps involved in heat transfer from tea to hand
Heat transfer from tea to head of spoon
Heat transfer from head of spoon to handle
Heat transfer from handle to hand
All these are examples of heat transfer by touch or contact
learning Objective-i HEAT TRANSFER by contact
learning Objective-i CONDUCTION
- Whenever two objects at different temperature come in contact (TOUCH) heat flows from the object at higher temperature to the object at lower temperature
- The transfer of heat by TOUCH or contact is called CONDUCTION
Conduction is also responsible for transfer of heat through a solid, from one end to another
question
Heat is transferred from tea to head of spoon by conduction
Heat is transferred from head of spoon to handle by conduction
Heat is transferred from handle to hand by conduction
experiment HEAT TRANSFER THROUGH A Solid
Learning objective
- Conduction is responsible for transferring heat from one part of the object to other parts
- In solids, generally, heat is transferred by the process of conduction
Question
Where else have you seen heat transferred from one part of the object to other parts?
experiment
Heat takes different time to travel the same distance through different materials
Learning Objective conductors & Insulators
- Objects in which heat transfers quickly from one end to
other are said to be good conductors of heat
- Objects in which heat transfer from one end to other is slow are said to be bad
conductors of heat
-
Poor conductors of heat are also called insulators.
Question
In this experiment, out of the 5 materials, which was the best conductor of heat? Look at the timings for information
Question
Which of these two materials would you prefer for a cooking pan's handle & why ?
a. Copper b. Steel c. Plastic
Challenges
The cylindrical rod is made of alternating metal & wooden strips. Paper is wrapped over the rod. video at 3:43
Why can we see burnt marks for wooden parts but no burnt marks for metallic
parts?
Hint :
Burnt
marks occur only when the paper reaches a certain temperature
ADVANCED Topics HOW is heat transferred from one end to the other?
ADVANCED TOPICS HOW IS HEAT TRANSFERRED FROM ONE END TO THE OTHER?
Conduction