ISRO Scientist or Engineer Mechanical 2007 Question 79

Question 79

A thin copper wire at $$300^\circ$$ is suddenly immersed in water at $$30^\circ C$$. It cools down to $$150^\circ C$$ in 70 seconds. It is then reheated to the initial temperature of $$300^\circ C$$ and suddenly exposedto air at $$30^\circ C$$ where it cools downto $$150^\circ C$$ in 200 seconds. This difference in cooling time is due to

Create a FREE account and get:

  • Download Maths Shortcuts PDF
  • Get 300+ previous papers with solutions PDF
  • 500+ Online Tests for Free


Register with


Boost your Prep!

Download App