Ask Questions, Get Answers

Want to ask us a question? Click here
Home  >>  JEEMAIN and AIPMT  >>  Physics  >>  Class11  >>  Thermodynamics
0 votes

Two rods of equal cross - section have their ratio of lengths 1 : 2 . If the ratio of their coefficient of thermal conductivity are in the ratio 3 : 4 , the ratio of time taken for heat transfer for same temperature differance is -

$(a)\;3 :8\qquad(b)\;8 :3 \qquad(c)\;2 : 3\qquad(d)\;3 : 2$

Can you answer this question?

1 Answer

0 votes
Answer : $2 : 3$
Explanation :
$\large\frac{\bigtriangleup Q}{\bigtriangleup t}=\large\frac{KA}{l}\;\bigtriangleup T$
$t \propto \large\frac{l}{k} \quad \;(for\; \bigtriangleup T and\; A\; same)$
$\large\frac{t_{1}}{t_{2}}=\large\frac{l_{1}}{l_{2}} . \large\frac{k_{2}}{k_{1}}=\large\frac{1}{2} \times \large\frac{4}{3}=\large\frac{2}{3}$
answered Mar 13, 2014 by yamini.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App