Question

The important characteristic of insulating refractory is

• A. High density
• B. High porosity
• C. High strength
• D. Metallic nature

Hint:

Insulating refractories have high porosity and low thermal conductivity.

Answer 1

The Correct Option is B

Concept: Insulating refractories are used to reduce heat loss. They have low thermal conductivity.

Step 1: Heat transfer is reduced when a material contains many pores.

Step 2: Air trapped inside pores is a poor conductor of heat.

Step 3: Therefore, high porosity reduces thermal conductivity.

Step 4: Insulating refractories are made light and porous so that they can act as thermal insulators.

Step 5: Hence, the important characteristic of insulating refractory is: \[ \boxed{\text{High porosity}} \]