Balbharati solutions for Physics [English] 11 Standard Maharashtra State Board chapter 7 - Thermal Properties of Matter [Latest edition]

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Range of temperature in a clinical thermometer, which measures the temperature of the human body, is

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A glass bottle completely filled with water is kept in the freezer. Why does it crack?

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If two temperatures differ by 25° C on Celsius scale, the difference in temperature on Fahrenheit scale is

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If α, β and γ are coefficients of linear, area l and volume expansion of a solid then

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Consider the following statements-

(I) The coefficient of linear expansion has dimension K^-1.

(II) The coefficient of volume expansion has dimension K^-1.

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Water falls from a hight of 200 m. What is the difference in temperature between the water at the top and bottom of a waterfall given that the specific heat of water is 4200 J kg^-1 °C-1?

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Clearly, state the difference between heat and temperature?

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How a thermometer is calibrated?

What are the different scales of temperature? What is the relation between them?

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What is absolute zero?

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Derive the relation between three coefficients of thermal expansion.

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State applications of thermal expansion.

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Why do we generally consider two specific heats of a gas?

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Are freezing point and melting point same with respect to change of state? Comment.

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Define Sublimation.

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Define Triple point.

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Explain the term 'steady state'.

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Define coefficient of thermal conductivity.

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Derive its expression for the coefficient of thermal conductivity.

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Give any four applications of thermal conductivity in everyday life.

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Explain the term thermal resistance. State its SI unit and dimensions.

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How heat transfer occurs through radiation in absence of a medium?

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State Newton’s law of cooling and explain how it can be experimentally verified.

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What is thermal stress?

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Give an example of the disadvantages of thermal stress in practical use?

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Which materials can be used as thermal insulators and why?

A glass flask has a volume 1 × 10⁻⁴ m³. It is filled with a liquid at 30°C. If the temperature of the system is raised to 100°C, how much of the liquid will overflow? (Coefficient of volume expansion of glass is 1.2 × 10⁻⁵ (°C)⁻¹ while that of the liquid is 75 × 10⁻⁵ (°C)⁻¹).

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Which will require more energy, heating a 2.0 kg block of lead by 30 K or heating a 4.0 kg block of copper by 5 K?
(s_lead = 128 J kg^–1 K^–1, `"s"_"copper"` = 387 J kg^–1 K^–1)

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Specific latent heat of vaporization of water is 2.26 × 106 J/kg. Calculate the energy needed to change 5.0 g of water into steam at 100 ºC.

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A metal sphere cools at the rate of 0.05 ºC/s when its temperature is 70 ºC and at the rate of 0.025 ºC/s when its temperature is 50 ºC. Determine the temperature of the surroundings and find the rate of cooling when the temperature of the metal sphere is 40 ºC.

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The volume of a gas varied linearly with absolute temperature if its pressure is held constant. Suppose the gas does not liquefy even at very low temperatures, at what temperature the volume of the gas will be ideally zero?

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In olden days, while laying the rails for trains, small gaps used to be left between the rail sections to allow for thermal expansion. Suppose the rails are laid at room temperature 27 °C. If maximum temperature in the region is 45 °C and the length of each rail section is 10 m, what should be the gap left given that α = 1.2 × 10^–5K^–1 for the material of the rail section?

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A blacksmith fixes iron ring on the rim of the wooden wheel of a bullock cart. The diameter of the wooden rim and the iron ring are 1.5 m and 1.47 m respectively at room temperature of 27 °C. To what temperature the iron ring should be heated so that it can fit the rim of the wheel? (α_iron = 1.2 × 10^–5K^–1).

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In a random temperature scale X, water boils at 200 °X and freezes at 20 °X. Find the boiling point of a liquid in this scale if it boils at 62 °C.

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A gas at 900 °C is cooled until both its pressure and volume are halved. Calculate its final temperature.

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An aluminium rod and iron rod show 1.5 m difference in their lengths when heated at all temperature. What are their lengths at 0 °C if coefficient of linear expansion for aluminium is 24.5 × 10^–6/°C and for iron is 11.9 × 10^–6/°C?

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What is the specific heat of metal if 50 cal of heat is needed to raise 6 kg of the metal from 20°C to 62 °C?

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The rate of flow of heat through a copper rod with temperature difference 30 °C is 1500 cal/s. Find the thermal resistance of copper rod.

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An electric kettle takes 20 minutes to heat a certain quantity of water from 0 °C to boiling point. It requires 90 minutes to turn all the water at 100 °C into steam. Find the latent heat of vaporization. (Specific heat of water = 1 cal/g °C)

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Find the temperature difference between two sides of a steel plate 4 cm thick, when the heat is transmitted through the plate at the rate of 400 k cal per minute per square meter at a steady state. Thermal conductivity of steel is 0.026 kcal/m s K.

A metal sphere cools from 80 °C to 60 °C in 6 min. How much time with it take to cool from 60 °C to 40 °C if the room temperature is 30 °C?