1 min read
Vacuum Flask
A vacuum flask reduces thermal-energy transfer between its contents and surroundings.
Choose Your Level
Vacuum Flask
Recommended for Class 10
Vacuum Flask
Vacuum Flask
A vacuum flask reduces thermal-energy transfer between its contents and surroundings.
Vacuum
The gap between the walls contains very little matter.
This strongly reduces:
conduction through the gap; convection through the gap.
Shiny Walls
Reflective surfaces reduce transfer by thermal radiation.
Stopper
An insulating stopper reduces conduction through the opening and limits air movement.
Narrow Neck
A narrow neck reduces the area available for heat transfer.
Critical Idea
A vacuum does not stop radiation.
That is why reflective surfaces are still necessary.
Vacuum Flask — Advanced
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
- Definition
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.
Ready to test yourself?
You've completed the learning section.
Practice
PQ
Q1. Explain the vacuum.
PQ
Q2. Explain shiny walls.
PQ
Q3. Explain the stopper.
PQ
Q4. Explain the narrow neck.
PQ
Q5. Why does radiation still matter?
Exam Practice
EQ
Q1. Describe a vacuum flask.
EQ
Q2. Explain vacuum function.
EQ
Q3. Explain reflective surfaces.
EQ
Q4. Explain the stopper.
EQ
Q5. Correct: vacuum stops all heat transfer.
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.