B M Sharma Solutions for Chapter: Thermometry, Thermal Expansion and Calorimetry, Exercise 2: CONCEPT APPLICATION EXERCISE

An electric heater whose power is $54 \mathrm{W}$ is immersed in $650 {\mathrm{cm}}^3$ water in a calorimeter. In $3 \min$ the water is heated by $3.4°\mathrm{C}$. What part of the energy of the heater passes out of the calorimeter in the form of radiant energy?

An ice cube whose mass is $50 \mathrm{g}$ is taken from a refrigerator where its temperature was $-10°\mathrm{C}$. If no heat is gained or lost from outside, how much water will freeze onto the cube if it is dropped into a beaker containing water at $0{}^{\circ }\mathrm{C}?$ Latent heat of fusion $=80 \mathrm{kcal}/\mathrm{kg}$, specific heat capacity of ice $=500 \mathrm{cal}/\mathrm{kg}/\mathrm{K}$

Equal volumes of three liquids of densities ${\rho }_1,{\rho }_2$ and ${\rho }_3$, specific heat capacities $c_1,c_2$ and $c_3$ and temperatures $t_1,t_2$ and $t_3$, respectively, are mixed together. What is the temperature of the mixture? Assume no changes in volume on mixing.

Victoria Falls in Africa is $122 \mathrm{m}$ in height. Calculate the rise in temperature of the water if all the potential energy lost in the fall is converted into heat.

Equal masses of three liquids $A, B$ and $C$ are taken. Their initial temperatures are $10°\mathrm{C},25°\mathrm{C}$ and $40°\mathrm{C}$, respectively. When $A$ and $B$ are mixed the temperature of the mixture is $19°\mathrm{C}$. When $B$ and $C$ are mixed, the temperature of the mixture is $35°\mathrm{C}$. Find the temperature if all three are mixed.

An earthenware vessel loses $1 \mathrm{g}$ of water per second due to evaporation. The water equivalent of the vessel is $0.5 \mathrm{kg}$ and the vessel contains $9.5 \mathrm{kg}$ of water. Find the time required for the water in the vessel to cool to $20°\mathrm{C}$ from $30°\mathrm{C}$. Neglect radiation losses. Latent heat of vaporization of water in this range of temperature is $540 \mathrm{cal}/\mathrm{g}$

A certain amount of ice is supplied heat at a constant rate for $7 \min$. For the first $1 \min$, the temperature rises uniformly with time; then it remains constant for the next 4 min and again rises at a uniform rate for the last $2 \min$. Explain physically these observations and calculate the final temperature. $L$ of ice $=336\times {10}^3 \mathrm{J}/\mathrm{kg}$ and $c_{\mathrm{water}}=4200 \mathrm{J}/\mathrm{kg}/\mathrm{K}$.

$1 \mathrm{g}$ steam at $100°\mathrm{C}$ is passed in an insulated vessel having $1 \mathrm{g}$ ice at $0°\mathrm{C}$. Find the equilibrium temperature of the mixture. Neglect heat capacity of the vessel.