Specific Heat Capacity

Q. Explain why (a) Two bodies at different temperatures T₁and T₂ if brought in thermal contact do not necessarily settle to the mean temperature (T₁ + T₂ )/2. (b) The coolant in a chemical or a nuclear plant (i.e., the liquid used to prevent the different parts of a plant from getting too hot) should have high specific heat. (c) Air pressure in a car tyre increases during driving. (d) The climate of a harbour town is more temperate than that of a town in a desert at the same latitude.

Q.

An ideal gas has volume $V_0$ at ${27}^{\circ }C$.It is heated at constant pressure so that its volume becomes $2V_0$. The final temperature is

1. 

2. 

3. 

4. 150 K

Q. A geyser heats water flowing at the rate of 3.0 litres per minute from 27 °C to 77 °C. If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 × 10⁴ J/g ?

Q. 1g H2 gas expand at STP to occupy double of its original volume. The work done during the process is?

Q. Two spheres $A$ and $B$ have diameters in the ratio $1:2$, densities in the ratio $2:1$ and thermal capacities in the ratio $1:12$. Find the ratio of their specific heat capacities.

1. $1:6$
2. $1:12$
3. $1:3$
4. $1:4$

Q. A block of mass 2.5kg is heated to temperature of 500^° C and placed on a large ice block.what is the maximum amount of ice that can melt(approx.) specific heat for the body=0.1cal/g^°

Q.

For an ideal gas of diatomic molecules

1. 

2. 

3. 

4. 

Q. 10g of ice cubes at 0 degree Celsius is released in a tumbler containing water having water equivalent = 55g at 40 degree Celsius . Assuming that negligible heat is taken from surroundings , the temperature of water in the tumbler becomes? (L=80cal/g)

Q.

A gas at NTP is suddenly compressed to one-fourth of its original volume.If $\gamma$ is supposed to be $\frac{3}{2}$, n then the final pressure is

1. 4 atmosphere

2. 

3. 8 atmosphere

4. 

Q. If specific heat of a substance is infinite, it means:

1. Heat is released.
2. Heat is absorbed.
3. Temperature does not change.
4. Infinite amount of heat is released.

Q.

An aluminum container of mass 100 g contains 200 g of ice at $-{20}^{\circ }C$. Heat is added to the system at a rate of $100cal{s}^{-1}$. Which of the following represents the variation in the temperature of the system as a function of time? Specific heat capacity of ice = $0.5cal{g}^{-1}$ ${}^{\circ }$$C^{-1}$, specific heat capacity of aluminum = $0.2cal{g}^{-1}$${}^{\circ }$ $C^{-1}$ and latent heat of fusion of ice = $80cal{g}^{-1}$.

1. 

2. 

3. None of these

4. 

Q. A sample of ideal gas is expanded to twice its original volume of 1.00metre cube in a quasi-static process for which p=αV^2, with α=5.00atm/m^6, How much work is done by the expanding gas?

Q. Which of the following is the correct unit for heat capacity?

1. ${\text{JK}}^{-1}{\text{kg}}^{-1}$
2. ${\text{JK}}^{-1}$
3. ${\text{Jkg}}^{-1}{{}^{\circ }\text{C}}^{-1}$
4. ${\text{JK}}^{-1}{\text{kg}}^{-1}$

Q.

Which of the following statements is true/correct

1. During clear nights, the temperature rises steadily upward near the ground level

2. Newton's law of cooling, an approximate form of Stefan's law, is valid only for natural convection

3. The total energy emitted by a black body per unit time per unit area is proportional to the square of its temperature in the Kelvin scale

4. Two spheres of the same material have radii 1 m and 4 m and temperatures 4000 K and 2000 K respectively. The energy radiated per second by the first sphere is greater than that radiated per second by the second sphere

Q. Given below are observations on molar specific heats at room temperature of some common gases. Gas Molar specific heat (Cv ) (cal mo1¯¹ K¯¹) Hydrogen 4.87 Nitrogen 4.97 Oxygen 5.02 Nitric oxide 4.99 Carbon monoxide 5.01 Chlorine 6.17 The measured molar specific heats of these gases are markedly different from those for monatomic gases. Typically, molar specific heat of a monatomic gas is 2.92 cal/mol K. Explain this difference. What can you infer from the somewhat larger (than the rest) value for chlorine ?

Q. Work done in converting one gram of ice at $-{10}^{\circ }\text{C}$ into steam at ${100}^{\circ }\text{C}$ is -
[Given, specific heat of ice $c_i=0.5{\text{cal g}}^{-1}{}^{\circ }{\text{C}}^{-1}$, specific heat of water $c_w=1{\text{cal g}}^{-1}{}^{\circ }{\text{C}}^{-1}$, latent heat of fusion of ice $L_f=80\text{cal/g}$, & latent heat of vaporization of steam $L_v=540\text{cal/g}$]

1. $725\text{J}$
2. $3045\text{J}$
3. $5023\text{J}$
4. $1128\text{J}$

Q. a carnot engine working between 300k and 600k has a work output of 800j per cycle. The amount of heat energy supplied to engine from the source in each cycle

Q. For a heat engine operating on carnot cycle the output is25% of the heat rejected to the surrounding atmosphere The thermal efficiency of engine is

Q. Three liquids with masses $m_1,m_2,m_3$ are thoroughly mixed, If their specific heats are $c_1,c_2,c_3$ and their temperatures $T_1,T_2,T_3$ respectively, then the temperature of the mixture is

1. $\frac{c_1{T}_1+c_2{T}_2+c_3{T}_3}{m_1{c}_1+m_2{c}_2+m_3{c}_3}$
2. $\frac{m_1{c}_1{T}_1+m_2{c}_2{T}_2+m_3{c}_3{T}_3}{m_1{c}_1+m_2{c}_2+m_3{c}_3}$
3. $\frac{m_1{c}_1{T}_1+m_2{c}_2{T}_2+m_3{c}_3{T}_3}{m_1{T}_1+m_2{T}_2+m_3{T}_3}$
4. $\frac{m_1{T}_1+m_2{T}_2+m_3{T}_3}{c_1{T}_1+c_2{T}_2+c_3{T}_3}$

Q. The average molar heat capacities of ice and water are 37.8j/mol and 75.6j/ mol. The amount of heat required to change 10g of ice at -10 ^° c to water at 10^° c would be (a) 2376j (b)4752j (c) 3970j (d)1128j (e)1985

Q.

A tube leads from a flask in which water is boiling under atmospheric pressure to a calorimeter. The mass of the calorimeter is $150gm$, its specific heat capacity is $0.1cal/gm{/}^{\circ }C$, and it contains originally $340gm$ of water at ${15}^{\circ }C$. Steam is allowed to condense in the calorimeter until its temperature increase to ${71}^{\circ }C$, after which total mass of calorimeter and contents are found to be $525gm$. Compute the heat of condensation of steam.

1. 539 cal/kg

2. 539 cal/gm

3. 639 cal/gm

4. 639 cal/kg

Q.

Water is used as a coolant in automobiles radiators because

1. it is cheap

2. it is easily available

3. it has high specific heat capacity

4. it is easy to carry

Q.

The pressure and density of a diatomic gas $(\gamma =\frac{7}{5})$ change adiabatically from (p, d) to (p', d'). If $\frac{d^{\prime }}{d}=32$, then $\frac{P^{\prime }}{P}$ should be.

1. 32

2. 1/128

3. 128

4. None of the above

Q. One mole of an ideal monoatomic gas undergoes a process described by the equation $P{V}^3=\text{constant}$. The molar heat capacity of this gas during this process is

1. $\frac{3}{2}R$
2. $\frac{5}{2}R$
3. $2R$
4. $R$

Q. 3.A refrigerator freezes 5 kg of water at 0^° C into ice at 0^° C in a time interval of 20 minutes. Assume that room temperature is 20^° C. Calculate the minimum power needed to accomplish it?

Q.

A piece of metal weight 46 gm in air, when it is immersed in the liquid of specific gravity 1.24 at ${27}^{\circ }C$ it weighs 30 gm. When the temperature of liquid is raised to ${42}^{\circ }C$ the metal piece weight 30.5 gm, specific gravity of the liquid at ${42}^{\circ }C$ is 1.20, then the linear expansion of the metal will be

1. 3.316 × 10^-5/ºC

2. 2.316 × 10^-5/ºC

3. 4.316 × 10^-5/ºC

4. None of these

Q. A pump on the ground floor of a building can pump up water to fill a tank of volume $30m^3$ in $15min$. If the tank is $40m$ above the ground, and the efficiency of the pump is $30\%$, how much electric power is consumed by the pump ?[Dencity of water ${10}^{3}kg{m}^{-3}$]$(g=9.8m{s}^{-2})$

Q. The K.E of mole of an ideal gas is $E=\frac{3}{2}\text{RT}$. Then $C_p$ will be

1. $0.5\text{R}$
2. $0.1\text{R}$
3. $1.5\text{R}$
4. $2.5\text{R}$

Q. One mole of an ideal monoatomic gas undergoes a process described by the equation $P{V}^3=\text{constant}$. The molar heat capacity of this gas during this process is

1. $\frac{3}{2}R$
2. $\frac{5}{2}R$
3. $2R$
4. $R$

Q. Statement 1: Heat capacity/Thermal capacity of a substance depends on mass of substance.
Statement 2: Specific heat capacity of a substance is independent of mass of substance.

1. Statement 1 is correct, statement 2 is incorrect.
2. Statement 1 is incorrect, statement 2 is correct.
3. Both statements are correct.
4. Both statements are incorrect.