Question

The insulating material used inside the immersion water heater tube is....

Answer 1

The insulating material used inside the immersion water heater tube is $\textbf{magnesium oxide}$

basically heater are of three types present in market , 1. normal plate heater , 2. immersion water heater 3. Geyser

immersion water heater is used for heating the water. in market from 250W to 2kW immersion heaters are available. The body of heater is made of Metallic substance and heating element is made of copper. which is installed inside the capillary tube. The capillary tube is filled with MgO which works as insulator.