Question

A wooden spoon is dipped in a cup of ice cream. its other end
1. becomes cold by the process of conduction
2. becomes cold by the process of convection
3. becomes cold by the process of radiation
4. does not become cold

Answer 1

Correct Answer - Option 4 : does not become cold

Explanation:​

• Conduction is the mode of transfer of heat in which heat is transferred from one end to another across a conductor. 
• Conductors include mostly metals that allow the transfer of heat across them. 
• Hotness or coldness both get transferred across conductor if there is temperature difference
• But wood is a bad conductor or insulator of heat. It does not allow heat to pass through it.
• So coldness is not transferred to the wooden spoons. 

'does not become cold' is correct.

Conduction: 

• The heat transfer through direct physical contact is known as conduction.
• Heat transferred from one end to other end is called conduction. 
• Heat transfer through conduction can only happen in conductors of heat like iron, copper etc. 
• Heat transfer do not take place across insulators like wood, plastic etc. 

Radiation: 

• When electromagnetic radiation is emitted or absorbed to transfer the heat or When heat is transferred in the form of electromagnetic waves is known as radiation.
• Electromagnetic radiation includes microwaves, radio waves, infrared radiation, visible light, ultraviolet radiation, gamma rays, and X-rays.
• The method does not require any medium so heat from the sun reaches us by this method.

Convection

• It is heat transfer by the movement of its molecules.
• It occurs only in fluids (liquid and gas) not in solids because solid particles can not move from one place to another.
• For example, in a pot boiling water on the stove, or in thunderstorms, where hot air rises up to the base of the clouds.