## Question

The dimensions of the coefficient of thermal conductivity are

### Solution

MLT^{– 3 }K^{– 1}

For a bar of cross-sectional area *A, *length *l* and having temperatures at its two ends, the amount of heat energy *Q* flowing normally across the bar in time *t * is given by

Where *k* is the coefficient of thermal conductivity. Therefore,

#### SIMILAR QUESTIONS

Two rods of different materials having coefficient of thermal expansion and Young’s modulii *Y*_{1} and *Y*_{2} are fixed between two rigid and massive walls. The rods are heated to the same temperature. If there is no bending of the rods, the thermal stresses developed in them are equal provided

300 g of water at 25^{o}C is added to 100 g of ice at 0^{o}C. The final temperature of the mixture is

100 g of ice at 0^{o}C is mixed with 100 g of water 80^{o}C. The final temperature of the mixture will be

Steam at 100^{o}C is passed into 1.1 kg of water contained in a calorimeter of water equivalent 0.02 kg at 15^{o}C till the temperature of the calorimeter rises to 80^{o}C. The mass of steam condensed in kilogram is

If there are no heat losses, the heat released by the condensation of *x*grams of steam at 100^{o}C into water 100^{o}C converts *y* grams of ice at 0^{o}C into water at 100^{o}C. The ratio *y*/*x *is nearly

One mole of oxygen is heated from 0^{o}C, at constant pressure, till its volume increases by 10%. The specific heat of oxygen, under these conditions is 0.22 cal g ^{– 1 }K^{ – 1}. The amount of heat required (in joules) is

A drilling machine of power *P* watts is used to drill a hole in copper block of mass *M* kg. If the specific heat of a copper is *s* J and 40% of the power is lost due to heating of the machine, the rise in the temperature of the block in *T* seconds will be (in ^{o}C)

A geyser, operating on LPG (liquefied petroleum gas) heats water flowing at the rate of 3.0 litres per minute, from 27^{o}C to 77^{o}C. If the heat of combustion of LPG is , how much fuel in grams is consumed per minute?

A copper block of mass 2 kg is heated to a temperature of 500^{o}C and then placed in a large block of ice at 0^{o}C. What is the maximum amount of ice that can melt? The specific heat of copper is 400 j and latent heat of fusion of water is .

Two different metal rods of the same length have their ends kept at the same temperatures and with . If *A* and *B *are their cross-sectional areas and *k*_{1} and *k*_{2} their thermal conductivities, the rate of flow of heat in the two rods will be the same if