four rods with different radii 'r' and length are used to connect two heat reservoir at different temperatures. which one will conduct more heat
The heat conduction per unit time is given by,
dq/dt = k(t - t)A/l
=> dq/dt = k(t - t)πr²/l
=> dq/dt ∝ r²/l
hence we can see that the heat conduction is directly proportional to the radius and inversely proportional to the length.
So heat conduction is maximum when r is maximum and l is minimum.
Hence the rod with maximum radius and minimum length will conduct maximum heat.
This is an important chapter too as 1 question is usually asked always especially in NEET or cet. So prepare well and keep practicing more and more mcqs to build your concepts strong.
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