Low specific heat and low thermal conductivityĭ.It sounds like you're thinking more along the lines of a transient type of problem than a steady-state type of problem: is that accurate? Whenever time becomes a variable, things obviously get more complicated. High specific heat and high thermal conductivityĬ. High specific heat and low thermal conductivityī.

Question 1: For cooking the food, which of the following type of utensil is most suitableĪ.

An electric heater is used in a room of total wall area 137 m 2 ( IIT JEE 1986).

A double pane window used for insulating a room thermally from outside (IIT JEE 1997).

A point source of heat of power P kept at the centre of a spherical shell (IIT JEE 1991).

MCQ on a composite block is made of slabs A, B, C, D, and E (IIT JEE 2011).Evaporation of water and melting of ice kepts at two ends of a metal rod AB of length 10x (IIT JEE 2009).Effective thermal conductivity of two concentric cylinders (IIT JEE 1988).Temperature at the vertex? (IIT JEE 1995) Three rods forms an isosceles triangle.Temperature at the junction of the three identical rods (IIT JEE 2001).Two conducting cylinders of equal length but different radii connected in series (IIT JEE 2018).Two rods connected in series and parallel (IIT JEE 2014).Two blocks connected in series and parallel ( IIT JEE 2013).The end Q and R of two thin wires, PQ and RS, are soldered (IIT JEE 2016).Solved Problems on Conduction Heat Transfer from IIT JEE At a given temperature T, the ratio of thermal conductivity (K) to the electrical conductivity (σ) is constant i.e., K/σT= L (a constant). In general, a substance that is a good conductor of heat is also a good conductor of electricity. If rods is parrallel are of same physical dimensions but thermal conductivities $K_1$ and $K_2$ then effective thermal conductivity of the system is

The effective thermal resistance of a system of two rods connected in parallel is given by If these rods are of same physical dimensions and of thermal conductivities $K_1$ and $K_2$ then effective thermal conductivity of the system is The effective thermal resistance of a system of two rods connected in series is given by In electrical circuits, equivalents of heat current, temperature difference and thermal resistance is electric current, potential difference and electrical resistance, respectively.Ĭonsider two rods of thermal resistances $R_1$ and $R_2$. The rate of heat transfer through a rod of length x and cross-section area A whose two ends are maintained at a temperature T 1 and T 2 is given by

Heat transfer in metal rod