JEE Main 202120 JulyMorning Shift
- Exam
- JEE Main
- Year
- 2021
- Date
- 20 July
- Shift
- Morning Shift
- Subject
- Chemistry
- Chapter
- Solid State
JEE Main 2021 · 20 July · Morning Shift · Chemistry · Solid State
Given below are two statements. One is labelled as Assertion A and...
Given below are two statements. One is labelled as
Assertion and the other is labelled as Reason .
Assertion Sharp glass edge becomes smooth on heating it up to its melting point.
Reason The viscosity of glass decreases on melting.
Choose the most appropriate answer from the options given below.
Options
- A is true but is false
- BBoth and are true but is NOT the correct
explanation of - C is false but is true.
- DBoth and are true and is the correct explanation of .
Correct answer
B. Both and are true but is NOT the correct
explanation of
Step-by-step solution
Sharp glass edges are heated to make them smooth. Because on heating glass melts and the surface of the liquid tends to take the rounded shape at the edges which has minimum surface area. This is called fire polishing of glass. Correct explanation for this is surface tension.