Thermal Properties of Matter MCQs for NEET — Physics Questions with Answers

An object is cooled from 75°C to 65°C in 2 minutes in a room at 30°C. The time taken to cool another object from 55°C to 45°C in the same room in minutes is -

A cane is taken out from a refrigerator at 0°C. The atmospheric temperature is 25°C. If ${\mathrm{t}}_1$ is the time taken to heat from 0°C to 5°C and ${\mathrm{t}}_2$ is the time taken from 10°C to 15°C, then 

A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is 36$°\mathrm{C}$. Then the difference of temperature at the two surfaces of A will be

Ice starts forming in lake with water at 0$°\mathrm{C}$ and when the atmospheric temperature is -10$°\mathrm{C}$. If the time taken for 1 cm of ice be 7 hours, then the time taken for the thickness of ice to change from 1 cm to 2 cm is

A cylinder of radius R made of a material of thermal conductivity ${\mathrm{K}}_1$ is surrounded by a cylindrical shell of inner radius R and outer radius 2R made of material of thermal conductivity ${\mathrm{K}}_2$. The two ends of the combined system are maintained at two different temperatures. There is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system is 

A room is maintained at 20$°\mathrm{C}$ by a heater of resistance 20 ohm connected to 200 volt mains. The temperature is uniform through out the room and heat is transmitted through a glass window of area $1{\mathrm{m}}^2$ and thickness 0.2 cm. What will be the temperature outside? Given that thermal conductivity K for glass is 0.2 cal/m $°\mathrm{C}$ and J = 4.2 J/cal

There is formation of layer of snow x cm thick on water, when the temperature of air is $-\mathrm{\theta }°\mathrm{C}$ (less than freezing point). The thickness of layer increases from x to y in the time t, then the value of t is given by

Three rods of identical area of cross-section and made from the same metal form the sides of an isosceles triangle ABC , right angled at B. The points A and B are maintained at temperatures T and $\sqrt{2}\mathrm{T}$ respectively. In the steady state the temperature of the point C is ${\mathrm{T}}_{\mathrm{C}}$. Assuming that only heat conduction takes place, $\frac{{\mathrm{T}}_{\mathrm{C}}}{\mathrm{T}}$ is equal to -

A sphere, a cube and a thin circular plate, all made of the same material and having the same mass are initially heated to a temperature of 1000°C. Which one of these will cool first ?

Two identical conducting rods are first connected independently to two vessels, one containing water at 100$°\mathrm{C}$ and the other containing ice at 0$°\mathrm{C}$. In the second case, the rods are joined end to end and connected to the same vessels. Let ${\mathrm{q}}_1$ and ${\mathrm{q}}_2$ g / s be the rate of melting of ice in two cases respectively. The ratio of is ${\mathrm{q}}_1$/${\mathrm{q}}_2$