Description : The heat supplied to the gaS at constant volume is (where m = Mass of gas, cv = Specific heat at constant volume, cp = Specific heat at constant pressure, T2 – T1 = Rise in temperature, and R = Gas constant) A. mR(T2 – T1) B. mcv(T2 – T1) C. mcp(T2 – T1) D. mcp(T2 + T1)
Last Answer : Answer: B
Description : Gas being heated at constant volume is undergoing the process of. a. isometric b. specific heat c. enthalpy d. isothermal
Last Answer : isometric
Description : Change in enthalpy of a system is the heat supplied at (a) constant pressure (b) constant temperature (c) constant volume (d) constant entropy (e) N.T.P. condition.
Last Answer : Answer : a
Description : As we heat a gas at constant pressure, its volume a. increases b. decreases c. stays the same d. none of the above
Last Answer : increases
Description : Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : c
Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Description : A gas having a volume of100 ft³ at 27ºC is expanded to 120 ft³by heated at constant pressure to what temperature has it been heated to have this new volume? a. 87°C b. 85°C c. 76°C d. 97°C t2= T2–T1
Last Answer : 87°C
Description : Gas is enclosed in a cylinder with a weighted piston as the stop boundary. The gas is heated and expands from a volume of 0.04 m^3 to 0.10 m^3 at a constant pressure of 200kPa.Calculate the work done by the system. A. 8 kJ B. 10 kJ C.12 kJ D.14 kJ Formula: W = p(V2-V1)
Last Answer : 12 kJ
Description : A gas is enclosed in a cylinder with a weighted piston as the top boundary. The gas is heated and expands from a volume of 0.04 m3 to 0.10 m3 at a constant pressure of 200 kPa. Find the work done on the system. a. 5 kJ b. 15 kJ c. 10 kJ d. 12 kJ
Description : A perfect gas at 27°C is heated at constant pressure till its volume is double. The final temperature is (a) 54°C (b) 327°C (c) 108°C (d) 654°C (e) 600°C
Last Answer : Answer : b
Description : If a gas is heated against a pressure, keeping the volume constant, then work done will be equal to (a) + v (b) – ve (c) zero (d) pressure x volume (e) any where between zero and infinity.
Description : The heat Q per unit mass per degree change in temperature that must be supplied or removed to change the temperature of a substance. a. Specific Heat Capacity b. Latent Heat c. Heat of Transformation d. Internal Heat
Last Answer : Specific Heat Capacity
Description : In an isothermal process, the internal energy of gas molecules (a) increases (b) decreases (c) remains constant (d) may increase/decrease depending on the properties of gas (e) shows unpredictable behaviour.
Description : A gas is compressed in a cylinder by a movable piston to a volume onehalf its original volume. During the process 300 kJ heat left the gas and internal energy remained same. The work done on gas in Nm will be (a) 300 Nm (b) 300,000 Nm (c) 30 Nm (d) 3000 Nm (e) 30,000 Nm.
Description : The cycle in which heat is supplied at constant volume and rejected at constant pressure is known as (a) Dual combustion cycle (b) Diesel cycle (c) Atkinson cycle (d) Rankine cycle (e) Stirling cycle.
Description : _____ is that property of a substance which remains constant if no heat enters or leaves the substance, while it does work or alters its volume, but which increases or diminishes should a small amount of heat enter or leave. a. Entrophy b. Enthalpy c. Specific Heat d. None of the above
Last Answer : Entrophy
Description : What is the resulting pressure when one pound of air at 15 psia and 200 ˚F is heated at constant volume to 800 ˚F? A.15 psia B. 28.6 psia C. 36.4 psia. D. 52.1 psia Formula : T1/p1 = T2/p2 p2= p1T2 / T1
Last Answer : 28.6 psia
Description : In an isothermal process, the internal energy (a) increases (b) decreases (c) remains constant (d) first increases and then decreases (e) first decreases and then increases.
Description : The volume of a gas under constant pressure increases or decrease with temperature. a. Gay- Lussac’s Law b. Ideal Gas Law c. Charles’ Law d. Boyle’s Law
Last Answer : Charles’ Law
Description : The volume of the gas held at constant pressure increases 4 cm² at 0°C to 5cm². What is the final pressure? a. 68.65ºC b. 68.25ºC c. 70.01°C d. 79.1ºC t2= T2–T1
Last Answer : 981 N
Description : The constant pressure, constant volume and constant pvn processes are regarded as irreversible process. A. True B. False
Last Answer : Answer: A
Description : Sum of the internal energy of a substance and the product of pressure and volume. a. Specific Heat b. Specific Gravity c. Isolated System d. Enthalpy
Last Answer : Enthalpy
Description : An ideal gas is compressed in a cylinder so well insulated that there is essentially no heat transfer. The temperature of gas a. Remains constant b. increases c. decreases d. is basically zero
Description : Which of the following occurs in a reversible polytrophic process? a. Enthalpy remains constant b. Internal energy does not change c. Some heat transfer occurs d. Entropy remains constant
Last Answer : Some heat transfer occurs
Description : According to first law of thermodynamics (a) work done by a system is equal to heat transferred by the system (b) total internal energy of a system during a process remains constant ( ... , enthalpy and entropy during a process remain constant (d) total energy of a system remains constant
Last Answer : Answer : d
Description : The volume of a confined gas is held constant, the pressure is directly proportional to the absolute temperature. a. Charle’s Law b. Boyle’s Law c. Joule’s Law d. Specific Heat
Last Answer : Boyle’s Law
Description : There are 1.36 kg of gas, for which R = 377 J/kg.k and k = 1.25, that undergo a nonflow constant volume process from p1 = 551.6 kPa and t1 = 60°C to p2 = 1655 kPa. During the process the gas is internally stirred and ... (Formula: T2= T1p2/ p1) a. 999 K b. 888 K c. 456 K d. One of the above
Last Answer : 999 K
Description : The specific heat at constant volume is A. the amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure B. the amount of heat required to raise ... to raise the temperature of 1 kg of water through one degree D. any one of the above
Description : The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called A.specific heat at constant volume B.specific heat at constant pressure C.kilo Joule D.none of these
Description : Addition of heat at constant pressure to a gas results in (a) raising its temperature (b) raising its pressure (c) raising its volume (d) raising its temperature and doing external work (e) doing external work.
Description : Universal gas constant is defined as equal to product of the molecular weight of the gas and (a) specific heat at constant pressure (b) specific heat at constant volume (c) ratio of two specific heats (d) gas constant (e) unity.
Description : According to Avogadro's Hypothesis (a) the molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature (b) the sum of partial pressure of ... gases have two values of specific heat (e) all systems can be regarded as closed systems.
Description : An ideal gas at 45psig and 80ºF is heated in the close container to 130ºF. What is the final pressure? a. 65.10 psi b. 65.11 psi c. 65.23 psi d. 61.16 psi P1V1/T1= P2V2/T2;V = Constant
Last Answer : 65.23 psi
Description : The volume of a given amount of water _________ as the temperature decreases from 4˚C to 0˚C. a. decreases b. increases c. remains constant d. none of the above
Description : Which of the following relations is not applicable in a free expansion process? a. Heat is rejected to zero b. Work done is zero c. Change in temperature is zero d. Heat supplied is zero
Last Answer : Change in temperature is zero
Description : The thermodynamic difference between a Rankine cycle working with saturated steam and the Carnot cycle is that (a) carnot cycle can't work with saturated steam (b) heat is supplied to water at temperature ... heat at two places (d) rankine cycle is hypothetical (e) none of the above.
Description : It states that mass is a commodity that can neither be heated nor destroyed with the exception of nuclear processes where the conversion of mass into energy is a fundamental principle a. Law of ... Conservation of Energy c. Law of Conservation of Power d. Law of Conservation of Heat
Last Answer : Law of Conservation of Mass
Description : According to Gay-Lussac law for a perfect gas, p/T = constant, if v is kept constant. A. True B. False
Description : Entropy is the measure of: a. The internal energy of a gas b. The heat capacity of a substance c. Randomness or disorder d. The change of enthalpy of a system
Last Answer : Randomness or disorder
Description : An adiabatic process is one in which A.no heat enters or leaves the gas B.the temperature of the gas changes C.the change in internal energy is equal to the mechanical workdone D.all of the above
Last Answer : Answer: D
Description : In the first law of thermodynamics, the total energy of the system remains constant. A. True B. False
Description : According to kinetic theory of gases, the absolute zero temperature is attained when (a) volume of the gas is zero (b) pressure of the gas is zero (c) kinetic energy of the molecules is zero (d) specific heat of gas is zero (e) mass is zero.
Description : Is a steady flow process at total constant pressure through a control volume for which there is no heat? a. Adiabatic Saturation Process b. Dew point c. Adiabatic Ratio d. None of the above
Last Answer : Adiabatic Saturation Process
Description : Ten cu. ft of air at 300psia and 400°F is cooled to 140°F at constant volume. What is the transferred heat? a.-120Btu b. -220Btu c.-320Btu d. -420Btu formula: Q= mcv(T2-T1)
Last Answer : -420Btu
Description : Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle A. combustion is at constant volume B. expansion and compression are isentropic C. maximum temperature is higher D. heat rejection is lower
Description : The value of specific heat at constant pressure (cp) is __________ that of at constant volume (cv). A. less than B. equal to C. more than
Last Answer : Answer: C
Description : The ratio of specific heat at constant pressure (Cp) and specific heat at constant volume (cv) is A. equal to one B. less than one C. greater than one D. none of these
Description : In a Carnot cycle, heat is transferred at (a) constant pressure (b) constant volume (c) constant temperature (d) constant enthaply (e) any one of the above.
Description : A heat exchange process in which the product of pressure and volume remains constant is known as (a) heat exchange process (b) throttling process (c) isentropic process (d) adiabatic process (e) hyperbolic process.
Last Answer : Answer : e
Description : Steam at 1000 lbf/ft^2 pressure and 300˚R has specific volume of 6.5 ft^3/lbm and a specific enthalpy of 9800 lbf-ft/lbm. Find the internal energy per pound mass of steam. A.2500 lbf-ft/lbm B.3300 lbf-ft/lbm C.5400 lbf-ft/lbm D.6900 lbf-ft/lbm Formula: h= u+ pV u= h– pV
Last Answer : 3300 lbf-ft/lbm