$Assertion :$ Two thin blankets put together are warmer than a single blanket of double the thickness.
$Reason :$ Thickness increases because of air layer enclosed between the two blankets.
AIIMS 2010, Easy
Download our app for free and get started
Two thin blankets put together are more warm because an insulating layer of air (as air is good insulator of heat) is enclosed between two blankets due to which it gives more warmness.
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
In an experment ot verify Newton's law of cooling, a graph is plotted between, the temperature difference $(\Delta T )$ of the water and surroundings and time as shown in figure. The initial temperature of water is taken as $80^{\circ} \,C$. The value of $t _{2}$ as mentioned in the graph will be...........
A solid sphere and a hollow sphere of the same material and size are heated to the same temperature and allowed to cool in the same surroundings. If the temperature difference between each sphere and its surroundings is $T$, then
A black body is at a temperature of $2880\;K$. The energy of radiation emitted by this object with wavelength between $499\;nm$ and $500\;nm$ is ${U_1}$, between $999\;nm$ and $1000\;nm$ is ${U_2}$ and between $1499\;nm$ and $1500\;nm$ is ${U_3}$. The Wein's constant $b = 2.88 \times {10^6}\;nm\,K$. Then
A copper pipe of length $10 \,m$ carries steam at temperature $110^{\circ} C$. The outer surface of the pipe is maintained at a temperature $10^{\circ} C$. The inner and outer radii of the pipe are $2 \,cm$ and $4 \,cm$, respectively. The thermal conductivity of copper is $0.38 kW / m /{ }^{\circ} C$. In the steady state, the rate at which heat flows radially outward through the pipe is closest to ............. $\,kW$
Radius of a conductor increases uniformly from left end to right end as shown in fig.Material of the conductor is isotropic and its curved surface is thermally isolated from surrounding. Its ends are maintained at temperatures $T_1$ and $T_2$ ($T_1$ > $T_2$): If, in steady state, heat flow rate is equal to $H$ , then which of the following graphs is correct
A body takes $5$ minutes to cool from $90^oC$ to $60^oC$. If the temperature of the surroundings is $20^oC$, the time taken by it to cool from $60^oC$ to $30^oC$ will be ...... $\min.$
For a black body at temperature $727^{\circ} C$, its radiating power is $60\; watt$ and temperature of surrounding is $227^{\circ} C$. If temperature of black body is changed to $1227^{\circ} C$ then its radiating power will be ..... $watt$
Four rods of indentical cross-sectional area and made from the same metal form the sides of a square. The temperature of two diagonally opposite points are $\theta$ and $\sqrt2 \theta$ respectively in the teady state. Assuming that only heat conduction takes place, what will be the temperature difference between other two points ?