JEE Main 2015 Physics question

A beaker contains a fluid of density , specific heat and viscosity . The beaker is filled up to height h. To estimate the rate of heat transfer per unit area by convection when beaker is put on a hot plate, a student proposes that it should depend on , and when (in C) is the difference in the temperature between the bottom and top of the fluid. In that situation the correct option for is:

• (1)Correct
• (2)
• (3)
• (4)