Physics-
General
Easy
Question
One end of a conducting rod is maintained at temperature 50°C and at the other end ice is melting at 0°C. The rate of melting of ice is doubled if
- the temperature is made 200°C and the area of cross-section of the rod is doubled
- the temperature is made 100°C and length of the rod is made four times
- area of cross section of rod is halved and length is doubled
- the temperature is made 100°C and area of cross-section of rod and length both are doubled
The correct answer is: the temperature is made 100°C and area of cross-section of rod and length both are doubled
Rate of melting of ice µ rate of heat transfer (dQ/dt).
Further 
or 
If temperature difference, A and l are all doubled then 
and hence, rate of melting of ice will be doubled.
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