Understanding Physics for JEE Main and Advanced Waves and Thermodynamics

DC Pandey, Arihant Experts

Chapter 22

Calorimetry \& Heat Transfer - all with Video Answers

Educators

Section 1

Calorimetry

Problem 1

$10 \mathrm{~g}$ ice at $0^{\circ} \mathrm{C}$ is converted into steam at $100^{\circ} \mathrm{C}$. Find total heat required. $\left(L_{f}=80 \mathrm{cal} / \mathrm{g}\right.$, $\left.S_{w}=1 \mathrm{cal} / \mathrm{g}-{ }^{\circ} \mathrm{C}, L_{v}=540 \mathrm{cal} / \mathrm{g}\right)$

Ankur S

Ankur S

Numerade Educator

Problem 2

Three liquids $A, B$ and $C$ of specific heats $1 \mathrm{cal} / \mathrm{g}-{ }^{\circ} \mathrm{C}, 0.5 \mathrm{cal} / \mathrm{g}-{ }^{\circ} \mathrm{C}$ and $0.25 \mathrm{cal} / \mathrm{g}-{ }^{\circ} \mathrm{C}$ are at temperatures $20^{\circ} \mathrm{C}, 40^{\circ} \mathrm{C}$ and $60^{\circ} \mathrm{C}$ respectively. Find temperature in equilibrium if they are mixed together. Their masses are equal.

Ankur S

Numerade Educator

Problem 3

Equal masses of ice (at $0^{\circ} \mathrm{C}$ ) and water are in contact. Find the temperature of water needed to just melt the complete ice.

Ankur S

Numerade Educator

Problem 4

A lead bullet just melts when stopped by an obstacle. Assuming that 25 per cent of the heat is absorbed by the obstacle, find the velocity of the bullet if its initial temperature is $27^{\circ} \mathrm{C}$. (Melting point of lead $=327^{\circ} \mathrm{C}$, specific heat of lead $=0.03 \mathrm{cal} / \mathrm{g}-{ }^{\circ} \mathrm{C}$, latent heat of fusion of $\begin{array}{ll}\text { lead }=6 \mathrm{cal} / \mathrm{g}, J=4.2 \mathrm{~J} / \mathrm{cal}) . & \text { (JEE 1981) }\end{array}$

Ankur S

Numerade Educator

Problem 5

The temperature of $100 \mathrm{~g}$ of water is to be raised from $24^{\circ} \mathrm{C}$ to $90^{\circ} \mathrm{C}$ by adding steam to it. Calculate the mass of the steam required for this purpose.

Ankur S

Numerade Educator

Problem 6

$15 \mathrm{~g}$ ice at $0^{\circ} \mathrm{C}$ is mixed with $10 \mathrm{~g}$ water at $40^{\circ} \mathrm{C}$. Find the temperature of mixture. Also, find mass of water and ice in the mixture.

Ankur S

Numerade Educator

Problem 7

Three liquids $P, Q$ and $R$ are given $4 \mathrm{~kg}$ of $P$ at $60^{\circ} \mathrm{C}$ and $1 \mathrm{~kg}$ of $R$ at $50^{\circ} \mathrm{C}$ when mixed produce $\mathrm{a}$ resultant temperature $55^{\circ} \mathrm{C}$. A mixture of $1 \mathrm{~kg}$ of $P$ at $60^{\circ} \mathrm{C}$ and $1 \mathrm{~kg}$ of $Q$ at $50^{\circ} \mathrm{C}$ shows a temperature of $55^{\circ} \mathrm{C}$. What will be the resulting temperature when $1 \mathrm{~kg}$ of $\mathrm{Q}$ at $60^{\circ} \mathrm{C}$ is mixed with $1 \mathrm{~kg}$ of $R$ at $50^{\circ} \mathrm{C}$ ?

Ankur S

Numerade Educator