Click the link for test preparation: Chapter 9 – Transfer of Heat

Online Test Instructions

•  Test Name : 9th Physics Chapter 9 Online Test
•  Type : MCQ's
•  Total Questions : 10
•  Total Marks : 10
•  Time : 10 minutes

•  Questions will be shuffled each time you start the test.
•  Any question you have not answered will be marked incorrect.
•  Once you are finished, click the View Results button.

This quiz must be completed in 10 minutes.

### This Post Has 8 Comments

1. Abdullah Hussain

Sir the Mcq

What happens to the thermal conductivity of a wall if its thickness is doubled?
Becomes double
remains the samewrong
Becomes halfcorrect
becomes one forth
It’s answer in the is wrong beacuse it remains same bacause it depends upon the nature of the object

1. Author

ok, we’ll check it.

1. FaminiB

As thermal conductivity is inversely proportional to length (thickness),so if thickness is doubled ,thermal conductivity will be halfed.This is according to formula of thermal conductivity.

2. Maryam

Sir the MCQ
Water is a
Good conductor
Poor conductor ❎
Super conductor ✅
Insulator
Sir it’s answer is wrong because heat travels in water by conduction and convection and it is written on pg 198 in for your information

1. Organizer

ok, we’ll check it.

3. Bushra

I got 10 out of 10 marks

1. tuka lag gya ho ga tumhara

4. ABDULLAH

The thermal conductivity of a wall is directly proportional to its thickness12. If the thickness of the wall is doubled, the thermal conductivity also becomes double12. This is because a larger cross-sectional area of the solid has a larger number of molecules and free electrons on each layer parallel to its cross-sectional area, resulting in a greater rate of flow of heat through the solid1. in
the MCQ that What happens to the thermal conductivity of a wall if its thickness is doubled?
Becomes double
remains the same wrong
Becomes half correct
becomes one forth