## Question

### Solution

Correct option is

Heat required to melt 15 gm of ice placed in the calorimeter will be 1200 cal

W = ms

or

The thermal capacity and the water equivalent of a body have the same numerical value.

Also                .

Since the temperature remains constant during the process of melting, no heat is exchanged with the calorimeter and hence

#### SIMILAR QUESTIONS

Q1

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

Q2

A copper block of mass 2 kg is heated to a temperature of 500oC and then placed in a large block of ice at 0oC. 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 .

Q3

The dimensions of the coefficient of thermal conductivity are

Q4

Two different metal rods of the same length have their ends kept at the same temperatures and  with . If A and are their cross-sectional areas and k1 and k2 their thermal conductivities, the rate of flow of heat in the two rods will be the same if

Q5

Two rods A and B of different materials are welded together as shown in Fig. If their thermal conductivities are k1 and k2 , the thermal conductivity of the composite rod will be

Q6

A one liter flask contains some mercury. It is found that at different temperatures the volume of air inside the flask remains the same. What is the volume of mercury in the flask? Given the coefficient of linear expansion of glass  oC–1, the coefficient of volume expansion of mercury is  oC–1.

Q7

A wire of cross-sectional area A at temperature t is held taut with negligible tension between two rigid supports. If the wire is cooled to a temperature  what tension is developed in the wire? The coefficient of linear expansion is  and the Young’s modulus of the wire is Y.

Q8

Two uniform brass rods A and of length l and 2and radii 2r and rrespectively are heated to the same temperature. The ratio of the increase in the length of A to that of B is

Q9

Two rods of different materials having coefficients of thermal expansion  and Young’s modulii Y1Y2 respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of the rods. If  the thermal stresses developed in the two rods are equal provided Y1 : Y2 is equal to:

Q10

A slab of stone of area 0.34 m2 and thickness 10 cm is exposed on the lower face to steam at 100oC. A block of ice at 0oC rests on the upper face of the slab. In one hour, 3.6 kg of ice is melted. Assume that the heat loss from the sides is negligible. The latent heat of fusion of ice is  What is the thermal conductivity of the stone in units of Js–1m–1oC–1?