JEE Advanced (Single Correct MCQs): Heat & Thermodynamics - Airforce X Y / Indian Navy SSR MCQ

An ideal monatomic gas is taken round the cycle ABCDA as shown in the P – V diagram (see Fig.). The  work done during the cycle is

If one mole of a monatomic gas   is mixed with one mole of a diatomic gas  , the value of γ for mixture is

From the following statements concerning ideal gas at any given temperature T, select the correct one(s)

Three rods of identical cross-sectional area and made from the same metal from the sides of an isosceles traingle ABC, right-angled at B. The points A and B are maintained at temperatures T and (√2) T respectively. In the steady state, the temperature of the point C is T_c. Assuming that only heat conduction takes place, T_c / T is

Two metallic spheres S₁ and S₂ are made of the same material and have got identical surface finish. The mass of S₁ is thrice that of S₂. Both the spheres are heated to the same high temperature and placed in the same room having lower temperature but are thermally insulated from each other. The ratio of the initial rate of cooling of S₁ to that of S₂ is 

The average translational kinetic energy of O₂ (relative molar mass 32) molecules at a particular temperature is 0.048 eV.
The translational kinetic energy of N₂ (relative molar mass 28) molecules in eV at the same temperature is

A vessel contains 1 mole of O₂ gas (relative molar mass 32) at a temperature T. The pressure of the gas is P. An identical vessel containing one mole of He gas (relative molar mass 4) at a temperature 2T has a pressure of

A spherical black body with a radius of 12 cm radiates 450 W power at 500 K. if the radius were halved and the temperature doubled, the power radiated in watt would be

A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity.Then the pressure in the compartment is 

 A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

The ratio of the speed of sound in nitrogen gas to that in helium gas, at 300 K is

 A monatomic ideal gas, initially at temperature T₁, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature T₂ by releasing the piston suddenly. If L₁ and L₂ are the length of the gas column before and after expansion respectively, 

then is given by

A block of ice at –10°C is slowly heated and converted to steam at 100°C. Which of the following curves represents the phenomenon qualitatively ?

An ideal gas is initially at temperature T and volume V. Its volume is increased by ΔV due to an increase in temperature ΔT, pressure remaining constant. The quantity
varies with temperature as

Starting with the same initial conditions, an ideal gas expands from volume V₁ to V₂ in three different ways. The work done by the gas is W₁ if the process is purely isothermal, W₂ if purely isobaric and W₃ if purely adiabatic. Then 

The plots of intensity versus wavelength for three black bodies at temperature T₁, T₂ and T₃  respectively are as shown. Their temperatures are such that

Three rods made of same material and having the same cross-section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at 0^oC and 90^oC respectively. The temperature of the junction of the three rods will be

In a given process on an ideal gas, dW = 0 and dQ < 0. Then for the gas 

P-V plots for two gases dur ing adiabatic pr ocesses are shown in the figure. Plots 1 and 2 should correspond respectively to

When a block of iron floats in mercury at 0^oC, fraction k₁ of its volume is submerged, while at the temperature 60^oC, a fraction k₂ is seen to be submerged. If the coefficient of volume expansion of iron is γ_Fe and  that of mercury is γ_Hg, then the ratio k₁/k₂ can be expressed as

An ideal gas is taken through the cycle  as shown in the figure. If the net heat supplied to the gas in the cycle is 5J, the work done by the gas in the process C⇒A is

Which of the followin g graphs cor rectly represents the variation of with P for an ideal gas at constant temperature ?

An ideal Black-body at room temperature is thrown into a furnace. It is observed that

The graph, shown in the adjacent diagram, represents the variation of temperature (T) of two bodies, x and y having same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity and absorptivity power of the two bodies

Two rods, one of aluminum and the other made of steel, having initial length l₁ and l₂ are connected together to form a single rod of length l₁ + l₂. The coefficients of linear expansion for aluminum and steel are α_a and α_s and respectively. If the length of each rod increases by the same amount when their temperature are raised by t⁰C, then find the ratiol₁/(l₁ + l₂)

The PT diagram for an ideal gas is shown in the figure, where AC is an adiabatic process, find the corresponding PV diagram.

2 kg of ice at –20⁰C is mixed with 5kg of water at 20⁰C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water remaining in the container. It is given that the specific heats of water & ice are 1kcal/kg/⁰C & 0.5 kcal/kg/⁰C while the latent heat of fusion of ice is 80 kcal/kg