-min%20(5).webp "basic-fitting-mcq")
01. Which of the following is not a property of the system?
Ans. (d) : Heat is not a property of the system it is the form of energy whereas temperature, pressure and volume are the property of the system.
02. 36. In reference to Thermodynamic equilibrium, it is required to have,
Ans. (d) : In reference to Thermodynamic equilibrium, it is required to have, Mechanical, Chemical and Thermal Equilibrium. For Mechanical equilibrium ∆ ≈ P 0 For Thermal equilibrium ∆ ≈ T 0 For Chemical equilibrium no change in concentration of reactants and products.
03.37. If the value of n is zero in the equation PVn = C, then the process is called
Ans. (b) : If the value of n is zero in the equation pVn = c, then the process is called constant pressure process.
04. In a free expansion of a gas between two equilibrium states, work transfer involved.
Ans. (c) : In a free expansion of a gas between two equilibrium states, work transfer involved is zero.
05.The internal energy of a substance depends on
Ans. (a) : The internal energy of a substance depends on temperature. U = mcV∆T
06. The temperature at which the volume of gas becomes zero is called
Ans. (b) : The temperature at which the volume of gas becomes zero is called absolute zero temperature. At absolute zero temperature (– 273.15 K), momentum of gas molecules becomes zero.
07.A fan consumes 20 W of electric power and discharges air from a ventilated room at 0.25 kg/s. The maximum air outlet velocity is nearly
(d) : Fan convert electrical energy into mechanical energy.
08. An isolated system-
Ans. (c) : Isolated system—An isolated system cannot transfer either energy or mass to or from the surrounding ∆m = 0, ∆E = 0 for isolated system. Example—Universe, thermal flask bottle etc.
09.In the polytropic process equation PVn = constant if n is infinitely large, the process is termed as-
Ans. (a) : In the polytropic process PVn = constant If n = ∞ then PV ∞ = constant. Then this polytropic process is termed as costant volume process. If n = 1 PV = constant (Isothermal process) If n = 0 PV0 = constant Constant pressure process If n = 1.4 PV1.4 = constant (adiabatic process) Process Value of 'n' index Constant pressure 0 Isothermal 1 Adiabatic 1.4 Constant volume ∞
10. The instrument which measures the temperature of the source without direct contact is
Ans. (c) : Pyrometer–Pyrometer is a device use for measuring relatively high temperature, such as are encountered in furnace. Most pyrometer works by measuring radiation from the body whose temperature is to be measured. Radiation devices have the advantage of not touch the material being measured.