One end of 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 of pure melting ice is :

When 1 g of ice melts at 0^@C

When ice melts at 1^(@)C :

When ice melts at 1^(@)C :

Two identical rods are connected in parallel. One end of the rods is maintained at 100^(@)C and other end is kept in 0^(@)C ice . The rate at which the ice melts is Q_(1) gm/sec . Now the rods are connected in series . The ends are again maintained at 100^(@) C and kept in 0^(@)C ice . Now the rate at which ice melts is Q_(2) gm/sec . Then Q_(2) //Q_(1) is

One end of the rod of length l, thermal conductivity K and area of cross-section A is maintained at a constant temperature of 100^@C . At the other end large quantity of ice is kept at 0^@C . Due to temperature difference, heat flows from left end to right end of the rod. Due to this heat ice will start melting. Neglecting the radiation losses find the expression of rate of melting of ice. .

One end of the rod of length l, thermal conductivity K and area of cross-section A is maintained at a constant temperature of 100^@C . At the other end large quantity of ice is kept at 0^@C . Due to temperature difference, heat flows from left end to right end of the rod. Due to this heat ice will start melting. Neglecting the radiation losses find the expression of rate of melting of ice. .

The container A contains ice at O^(@)C . A conducting uniform rod PQ of length 4R is used to transfer heat to the ice in the container. The end P of the rod is maintained at 100^(@)C and the other end Q is kept inside container A. The complete ice melts in 23 minutes. In another experiment, two conductors in shape of quarter circle of radii 2R and R are welded to the conductor PQ at M and N respectively and their other ends are inserted inside the container A. All conductors are made of same material and have same cross sectional area. Once again the end P is maintained at 100^(@)C and this time the com- plete ice melts in t min- ute. Find t. Assume no heat loss from the curved surface of the rods. [Take pi~=3.0 ]