Thermal properties of matter practice · Mixed difficulty

A piece of metal weighs $46 \mathrm{~g}$ in air. When immersed in a liquid of specific gravity $1.24$ at $27^{\circ} \mathrm{C}$ it weighs $30 \mathrm{~g}$. When the temperature of liquid is raised to $42^{\circ} \mathrm{C}$ the metal piece weighs $30.5 \mathrm{~g}$. Specific gravity of liquid at $42{ }^{\circ} \mathrm{C}$ is $1.20.$ Calculate the coefficient of linear expansion of metal

An electric bulb of volume 250 cc was sealed during manufacturing at a pressure of ${10^{ - 3}}\,\,{\text{mm}}\,\,{\text{of}}\,\,\,{\text{Hg}}$ at $27^\circ C.$ Number of air molecules contained in the bulb is

Assertion: It is hotter over the top of a fire than at the same distance on the sides.
Reason: Air surrounding the fire transfer more heat upwards.

When a bimetallic strip made of iron $\left( {{\alpha _1}} \right)$ and copper $\left( {{\alpha _2}} \right)$ is heated $\left( {{\alpha _2} > {\alpha _1}} \right)$

A hot body will radiate heat most rapidly if its surface is

A gas at the temperature $250\;K$ is contained in a closed vessel. If the gas is heated through $1K,$ then the percentage increase in its pressure will be

Statement-I: A thin rod and a thick rod made of same material having same length are heated through same range of temperature. Then both the rods expand equally.
Statement-II: The linear expansion $e=l \alpha \Delta t$

The pressure measured by a constant volume gas thermometer is $40 \mathrm{kPa}$ at the triple point of water. What will be the pressure measured at the boiling point of water $\left(100^{\circ} \mathrm{C}\right)$ ?

Identify the pair of physical quantities which have different dimensions.

Calorimeters are made of which of the following

(A): A brass tumbler feels much colder than a wooden tray on a chilly day.
(R): The thermal conductivity of brass is less than that of wood.

(A): The specific heat capacity of a given solid can be determined by using the principle of calorimetry.
(R): Heat gained is equal to the heat lost

In which of the following heat loss is primarily not due to convection?

The ends of 2 different materials with their thermal conductivities, radii of cross section and length all in the ratio of $1\;:2$ maintained at temperature difference. If the rate of the flow of heat in the longer rod is 4 cal${\mathrm{s}^{ - 1}}$, that in the shorter rod in cal${\mathrm{s}^{ - 1}}$ will be

Maximum density of ${H_2}O$ is at the temperature

A copper sphere is suspended in an evacuated chamber maintained at $300 \mathrm{~K}$. The sphere is maintained at a constant temperature of $500 \mathrm{~K}$ by heating it electrically. A total of $300 \mathrm{~W}$ of electric power is needed to do it. When half of the surface of the copper sphere is completely blackened $600 \mathrm{~W}$ is needed to maintain the same temperature of the sphere. Calculate the emissivity of copper.

Assertion (A): Real gases behave like an ideal gas at low densities
Reason (R): At low densities interaction between molecules in a gas is less

The temperature on Celsius scale is ${25^\mathrm{o}}C$. What is the corresponding temperature on the Fahrenheit scale

Two bars of copper having same length but unequal diameter are heated to the same temperature. The change in length will be

Statement A: Thermal radiations are electromagnetic radiation with wave lengths greater than visible light.
Statement B: Thermal radiations can propagate through vacuum.

On the Celsius scale the absolute zero of temperature is at

If a ball of $70 \mathrm{~kg}$ mass hits an ice cube and temperature of ball is $100^{\circ} \mathrm{C}$, then how much ice converted into water? (Specific heat of ball is $0.2 \mathrm{~cal} \mathrm{~g}^{-1}$, Latent heat of ice $=80 \mathrm{~cal} \mathrm{~g}^{-1}$)

On a hilly region, water boils at ${95^0}C$.The temperature expressed in Fahrenheit is

There is some change in length when 33000 N tensile force is applied on a steel rod of area of cross section ${10^{ - 3}}{m^2}$ . The change in temperature required to produce the same elongation of elasticity is $3 \times {10^{11}}\,N/{m^2}$ and the co-efficient of linear expansion of steel is $1.1 \times {10^{ - 5}}/{\,^ \circ }C$

An icebox made of $1.5 \mathrm{~cm}$ thick styrofoam has dimensions $60 \mathrm{~cm} \times 60 \mathrm{~cm} \times 30 \mathrm{~cm}$. It contains ice at $0^{\circ} \mathrm{C}$ and is kept in a room at $40^{\circ} \mathrm{C}$. Find the rate at which the ice is melting. Latent heat of fusion of ice $=3.36 \times 10^5 \mathrm{~J} \mathrm{~kg}^{-1}$. and thermal conductivity of styrofoam $=0.04 \mathrm{~W} \mathrm{~m}^{-1}{ }^{\circ} \mathrm{C}^{-1}$.

A brass disc fits simply in a hole of a steel plate. The disc from the hole can be loosened if the system

Statement-I: When a bimetallic strip made of iron and brass is heated then it bends in the form of concave towards Brass.
Statement-II: The coefficient of linear expansion of iron is less than brass.

Statement I: A special type of thermometer (used to measure very high temperatures and calibrated for an ideal black body) measures a value lower than the actual value of the temperature of a red hot iron piece kept in open.

Statement II: As the iron piece is kept in open, it loses its heat.

With rise in temperature, density of a given body changes according to one of the following relations

A beaker is completely filled with water at ${4^0}C$. It will overflow