# NCERT Class 11 Physics Solutions: Chapter 11 – Thermal Properties of Matter-Part 9

Get top class preparation for NSO-Level-2 Class-5 right from your home: fully solved questions with step-by-step explanation- practice your way to success.

Download PDF of This Page (Size: 97K) ↧

**Question 11.20:**

A brass boiler has a base area and thickness. It boils water at the rate of when placed on a gas stove. Estimate the temperature of the part of the flame in contact with the boiler. Thermal conductivity of brass ; Heat of vaporisation of water

**Answer:**

Base area of the boiler,

Thickness of the boiler,

Boiling rate of water,

Mass,

Time,

Thermal conductivity of brass,

Heat of vaporization,

The amount of heat flowing into water through the brass base of the boiler is given by:

Where,

Temperature of the flame in contact with the boiler

Boiling point of water

Heat required for boiling the water:

Equating equations (i) and (ii), we get:

Therefore, the temperature of the part of the flame in contact with the boiler is