AIIMS Physics Thermal Properties Of Matter Class 11 Questions

The formula for the bulk modulus is, β = -P / (ΔV / V). The formula for the compressibility is, K = 1/β = -ΔV / VP. Rewrite the above equation. -ΔV = KPV. Substitute the values in the above equation.

α = ΔL / L₀(Δθ) = 0.19 cm / 100 cm(100°C - 0°C) = 1.9×10⁻⁵ / °C The coefficient of cubical expansion is Y = 3α = 3×1.9×10⁻⁵ / °C = 5.7×10⁻⁵ / °C

The coefficient of apparent expansion of mercury in a glass vessel is $153 \times 10^{-6} /^\circ\text{C}$ and in steel vessel is $144 \times 10^{-6} /^\circ\text{C}$. If $\alpha$ for steel is $12 \times 10^{-6} /^\circ\text{C}$, then that of glass is

Assertion: The thermal resistance of a multiple layers laminas is equal to the sum of the thermal resistance of the individual lamina. Reason: Heat transferred is directly proportional to the temperature gradient in each layer.

Assertion: A spherical water drops become flat on flatter surface. Reason: It becomes flat due to gravity.

The formula for the resistance is, Rₜ = R₀ (¹⁺ αt). Initially, 10 = R₀ (1 + 30α). Final, 11 = R₀ (¹⁺ αt). Now,

The coefficient of cubical expansion of mercury is 0.00018/°C and that of brass is 0.00006/°C. If a barometer having a brass scale were to read 74.5 cm at 30°C, find the true barometric height at 0°C. The scale is supposed to be correct at 15°C

Two conductors having same width and length, thickness d₁ and d₂, thermal conductivity K₁ and K₂ are placed one above the another. Find the equivalent thermal conductivity.

Calculate the heat emitted by a bulb of 100 W in 1 min.

Assertion : Maximum air flow due to convection does not occur at the north pole but it occurs at 30° N. Reason : There is maximum temperature difference between equator and 30° N

Emissive and absorptive power of a material at 2000 K is 8 and 10 respectively, calculate the emissivity of IBB (Ideal black body)

The latent heat of vaporisation of a substance is always

Assertion: Water kept in an open vessel will quickly evaporate on the surface of the moon. Reason: The temperature at the surface of the moon is much higher than boiling point of water.

Black holes in orbit around a normal star are detected from the earth due to the frictional heating of infalling gas into the black hole, which can reach temperatures greater than 10⁶ K. Assuming that the infalling gas can be modelled as a blackbody radiator, then the wavelength of maximum power lies

Assertion : When hot water is poured in a beaker of thick glass, the beaker cracks. Reason : Outer surface of the beaker expands suddenly.

A slab consists of two layers of different materials of the same thickness and having thermal conductivities K₁ and K₂ are connected in series.

Shear modulus is zero for

A bimetallic strip consists of metals X and Y. It is mounted rigidly at the base as shown. The metal X has a higher coefficient of expansion compared to that for metal Y. When the bimetallic strip is placed in a cold bath

For a constant hydraulic stress on an object, the fractional change in the object’s volume (ΔV/V) and its bulk modulus (B) are related as

Assertion : For higher temperatures the peak emission wavelength of a black body shifts to lower wavelengths. Reason : Peak emission wavelengths of a blackbody is proportional to the fourth-power of temperature.

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

The density of a substance at 0°C is 10 g/cc and at 100°C, its density is 9.7 g/cc. The coefficient of linear expansion of the substance is

Assertion : Blue star is at high temperature than red star. Reason : Wein's displacement law states that T ∝ (1/λ).

Colour of a star depends upon

A solid sphere and a hollow sphere are heated to the same temperature. Point out the true statement.

1 Kcal of heat flowing through a rod of iron. When the rod is cut down to 4 pieces then what will be the heat flowing through each piece having same differential temperature?

Temperature of the star is determined by

A constant pressure air thermometer gave a reading of 47.5 units of volume when immersed in ice-cold water, and 67 units in a boiling liquid. The boiling point of the liquid, is

For an enclosure maintained at 1000 K, the maximum radiation occurs at wavelength λₘ. If the temperature is raised to 2000 K, the peak will shift to

Maximum wavelength of 350 nm. What is the ratio of surface temperature of the Sun and the star x?

Surface temperature of star A and B are 727°C and 327°C respectively. What is the ratio Hₐ : Hᵦ for the heat radiated per second by the two stars?

Assertion: Air at some distance above the fire is hotter than the same distance below it. Reason: Air surrounding the fire carries heat upwards.