Thermal Physics Mock Tests

A Carnot engine operates between temperatures T₁ = 500 K and T₂ = 300 K. It absorbs 2000 J of heat from the hot reservoir per cycle. The work done per cycle and the efficiency respectively are:

At a given temperature, the ratio of the root-mean-square speeds of O₂ molecules (molar mass 32 g/mol) to H₂ molecules (molar mass 2 g/mol) is:

One mole of an ideal diatomic gas (γ = 1.4) undergoes a cyclic process consisting of: (i) isothermal expansion from volume V to 2V at temperature T₀ = 400 K, followed by (ii) isobaric compression back to volume V. The net work done by the gas during the isothermal expansion is:

A copper block of mass 2 kg at 100 C is placed on a large ice block at 0 C. If the specific heat of copper is 0.4 kJ/kg.K and the latent heat of fusion of ice is 334 kJ/kg, the mass of ice melted is approximately

1 kg of water at 100°C is mixed with 1 kg of water at 0°C in an insulated container. The total entropy change of the system is approximately (take c = 4200 J/kg·K):

Two identical metallic spheres A and B are made of the same material. Sphere A is hollow and sphere B is solid. Both are heated to the same temperature and then allowed to cool under identical conditions. The ratio of their initial rates of cooling is:

An ideal gas undergoes an adiabatic compression from volume V to V/2. If the initial pressure is P₀ and γ = 1.5, the final pressure is:

Two rods A and B of same length and same mass but different densities ρ_A and ρ_B (ρ_A > ρ_B) have their ends maintained at temperatures T₁ and T₂ respectively. If the rate of heat flow through rod A is greater than through rod B, then the thermal conductivities K_A and K_B satisfy: