Thermal properties of matter practice · Mixed difficulty

What force should be applied to the ends of steel rod of a cross sectional area 10 cm2 to revent it from elongation when heated from 273K to 303K. $\left( {\alpha = 1 \times {{10}^{ - 5}}/{\,^{\,0}}C,y = 2 \times {{10}^{11}}\,w/{m^2}} \right)$

Certain amount of heat is given to $100 \mathrm{~g}$ of copper to increase its temperature by $21^{\circ} \mathrm{C}$. If the same amount of heat is given to $50 \mathrm{~g}$ of water, then the rise in its temperature is

(Take, specific heat capacity of copper

$=400 \mathrm{Jkg}^{-1} \mathrm{~K}^{-1}$ and that for water

$=4200 \mathrm{~J} \mathrm{~kg}^{-1} \mathrm{~K}^{-1}$ )

Assertion: A change in the temperature of a body causes change in its dimensions.
Reason: The dimensions of a body decrease due to the increase in its temperature.

If a carved black utensil is heated to high temperature and then brought in dark then:

Two beakers A and B are filled to the brim with water at ${4^0}C$ . When A is heated and B is cooled, the water

When a copper ball is heated, the largest percentage increase will occur in its

Assertion: Maximum air flow due to convection does not occur at the north pole but it occurs at $30^{\circ} \mathrm{N}$.
Reason: There is maximum temperature difference between equator and $30^{\circ} \mathrm{N}$.

A black body at a temperature of 1640 K has the wavelength corresponding to maximum emission equal to $1.75\mu$. Assuming the moon to be a perfectly black body, the temperature of the moon, if the wavelength corresponding to maximum emission is $14.35\mu$ is

A body having a temperature of $27^{\circ} \mathrm{C}$ is kept in a room having a temperature of $27^{\circ} \mathrm{C}$. Does the body emit any radiation in this case when the room temperature is the same as body temperature?

A thermometer graduated according to a linear scale reads a value ${x_0}$, when in contact with boiling water and ${x_0}\mathrm{/}3$ when in contact with ice. What is the temperature of an object in $^\circ C$, if this thermometer in the contact with the object reads ${x_0}\mathrm{/}2?$

For a cube, cylinder and sphere, linear dimension is same and these are made up by same material and having same surface and same temperature it these are placed in same temperature surrounding then find out the order of rate of heat loss and rate of cooling.

$19 \mathrm{~g}$ of water at $30^{\circ} \mathrm{C}$ and $5 \mathrm{~g}$ of ice at $-20^{\circ} \mathrm{C}$ are mixed together in calorimeter. What is the final temperature of the mixture? Given specific heat of ice $=0.5 \,\mathrm{cal} \,\mathrm{g}^{-1}\left({ }^{\circ} \mathrm{C}\right)^{-1}$ and latent heat of fusion of ice $=80\,cal\,{g^{ - 1}}$

A liter of air is heated from ${27^0}C$ to ${177^0}C$ at constant pressure. Find its volume

Inside a cylinder closed at both ends is a movable piston. On one side of the piston is a mass $m$ of a gas, and on the other side a mass 2 $m$ of the same gas. What fraction of the volume of the cylinder will be occupied by the larger mass of the gas when the piston is in equilibrium? The temperature is the same throughout.

Which of the following statement does not hold good for thermal radiation?

The sprinkling of water reduces slightly the temperature of a closed room because

We find that the temperature of air decreases as one goes up from the earth’s surface because

An iron ball having a surface area of $200 \mathrm{~cm}^2$ and at a temperature of $527^{\circ} \mathrm{C}$ is placed in an enclosure at $27^{\circ} \mathrm{C}$. If the surface emissivity of iron be $0.4,$ at what rate is heat being lost by radiation by the ball?

The length of a metal rod at ${0^0}C$ is $0.5\,m$. When it is heated, its length increases by $2.7\,mm$. The final temperature of rod is $\left[ {\alpha = 90 \times {{10}^{ - 61}}^0C} \right]$

Two cylinders P and Q have the same length and diameter and are made of different materials having thermal conductivities in the ratio 2:3. These two cylinders are combined to make a cylinder. One end of P is kept of ${100^0}C$ and another end of Q at ${0^0}C$. The temperature at the interface of P and Q is

The wavelength of the radiation emitted by a body depends upon

The tungsten filament of an electric lamp has a surface $A$ area and a power rating $P$. If the emissivity of the filament is $\varepsilon$ and $\sigma$ is Stefan’s constant, the steady temperature of the filament will be

A particular star (assuming it as a block body has a surface temperature of about $5 \times {10^4}K.$ The wavelength in nanometers at which its radiation becomes maximum is $(b = 0.0029\,\,mk)$

Assertion (A): At constant temperature, when pressure of a gas is increased by $10 \%$, then volume decreases by less than $10 \%$
Reason (R): At constant temperature the volume of gas is inversely proportional to the pressure acting on it.

(A): Two bodies at different temperatures, if brought in thermal contact do not necessary settle to the mean temperature.
(R): The two bodies may have different thermal capacities.

Heat is associated with

In an isochoric process if ${T_1} = {27^\mathrm{o}}C\mathrm{ }\,\,\,\mathrm{and}\,\,\,\mathrm{ }{T_2} = {127^\mathrm{o}}C$, then ${P_1}/{P_2}$ will be equal to

Assertion (A): Sometimes water pipes burst in severe winter.
Reason (R): On freezing water expands due to anamolous expansion.

Estimate the rate at which ice would melt in a wooden box $2.0 \mathrm{~cm}$ thick and of inside measurements $200 \mathrm{~cm} \times 120 \mathrm{~cm} \times 120 \mathrm{~cm}$ assuming that the external temperature is $30^{\circ} \mathrm{C}$ and coefficient of thermal conductivity of wood is $0.0004 \mathrm{~cal} \mathrm{~s}^{-1} \mathrm{~cm}^{-1}{ }^{\circ} \mathrm{C}$.

The latent heat of vaporization of a substance is always