Multiple choice question for engineering
Set 1
1. At constant temperature the pressure of an ideal gas is doubled its density becomes
a) Half
b) Double
c) Same
d) None
Answer
Answer: b [Reason:] Density is proportional to pressure.
2. For an ideal gas, incorrect statement is
a) Molecules do not occupy any space
b) No attractive force exist between the molecules
c) The gas molecules move in random, straight line motion
d) None of the mentioned
Answer
Answer: d [Reason:] Conditions for a gas to behave as predicated by the ideal gas law.
3. Correct statement is
a) Gases at low pressure or high temperature behave as an ideal gas
b) Gases at high pressure or low temperature behave as an ideal gas
c) Gases at high density behave as an ideal gas
d) None of the mentioned
Answer
Answer: a [Reason:] Gases at low pressure or high temperature behave as an ideal gas.
4. What is the volume of 20 gms of Oxygen in Litre at standard conditions?
a) 10
b) 12
c) 14
d) 16
Answer
Answer: c [Reason:] At standard conditions, 1 mole of of gas occupy 22.4 litre volume.
5. What is the density of Carbon-di-oxide in kg/m3 at 27 degree celcius and 100 KPa?
a) 1.76
b) 2.76
c) 3.76
d) 4.76
Answer
Answer: a [Reason:] density = (Pressure*Molecular weight)/(Gas constant*Temperature).
6. Usually while measuring the specific gravity of a gas, the reference gas that is taken is air.
The above given statement is-
a) False
b) True
c) Depends on the gas
d) None of the mentioned
Answer
Answer: b [Reason:] Air is usually taken at the same temperature and pressure.
7. What is the volume of 2.5 gm moles Nitrogen gas at STP? At 100 KPa pressure and 300 K temperature, 2 gm moles of the gas occupy 20 cubic meter volume.
a) 11.23
b) 22.46
c) 33.69
d) 44.92
Answer
Answer: d [Reason:] P1V1/n1T1 = P2V2/n2T2.
8. Which one has the lowest density at room temperature?
a) Ne
b) N2
c) NH3
d) CO
Answer
Answer: c [Reason:] NH3 have minimum molecular weight.
9. 1 atm pressure and 0°C’ condition is known as
a) Room temperature and pressure
b) Standard temperature and pressure
c) Atmospheric temperature and pressure
d) None of the mentioned
Answer
Answer: b [Reason:] 1 atm pressure and 0°C condition is known as standard temperature and pressure (STP).
10. At standard conditions, what is the volume of 1 kg mole of ideal gas?
a) 22.4 m3
b) 2240 m3
c) 224000 m3
d) None of the mentioned
Answer
Answer: a [Reason:] V = nRT/P.
Set 2
1. At constant temperature the pressure of an ideal gas is doubled its density becomes
a) Half
b) Double
c) Same
d) None
Answer
Answer: b [Reason:] Density is proportional to pressure.
2. For an ideal gas, incorrect statement is
a) Molecules do not occupy any space
b) No attractive force exist between the molecules
c) The gas molecules move in random, straight line motion
d) None of the mentioned
Answer
Answer: d [Reason:] Conditions for a gas to behave as predicated by the ideal gas law.
3. Correct statement is
a) Gases at low pressure or high temperature behave as an ideal gas
b) Gases at high pressure or low temperature behave as an ideal gas
c) Gases at high density behave as an ideal gas
d) None of the mentioned
Answer
Answer: a [Reason:] Gases at low pressure or high temperature behave as an ideal gas.
4. What is the volume of 20 gms of Oxygen in Litre at standard conditions?
a) 10
b) 12
c) 14
d) 16
Answer
Answer: c [Reason:] At standard conditions, 1 mole of of gas occupy 22.4 litre volume.
5. What is the density of Carbon-di-oxide in kg/m3 at 27 degree celcius and 100 KPa?
a) 1.76
b) 2.76
c) 3.76
d) 4.76
Answer
Answer: a [Reason:] density = (Pressure*Molecular weight)/(Gas constant*Temperature).
6. Usually while measuring the specific gravity of a gas, the reference gas that is taken is air.
The above given statement is-
a) False
b) True
c) Depends on the gas
d) None of the mentioned
Answer
Answer: b [Reason:] Air is usually taken at the same temperature and pressure.
7. What is the volume of 2.5 gm moles Nitrogen gas at STP? At 100 KPa pressure and 300 K temperature, 2 gm moles of the gas occupy 20 cubic meter volume.
a) 11.23
b) 22.46
c) 33.69
d) 44.92
Answer
Answer: d [Reason:] P1V1/n1T1 = P2V2/n2T2.
8. Which one has the lowest density at room temperature?
a) Ne
b) N2
c) NH3
d) CO
Answer
Answer: c [Reason:] NH3 have minimum molecular weight.
9. 1 atm pressure and 0°C’ condition is known as
a) Room temperature and pressure
b) Standard temperature and pressure
c) Atmospheric temperature and pressure
d) None of the mentioned
Answer
Answer: b [Reason:] 1 atm pressure and 0°C condition is known as standard temperature and pressure (STP).
10. At standard conditions, what is the volume of 1 kg mole of ideal gas?
a) 22.4 m3
b) 2240 m3
c) 224000 m3
d) None of the mentioned
Answer
Answer: a [Reason:] V = nRT/P.
Set 3
1. _________ represents a microscopic account of all the molecular, atomic, and subatomic energies.
a) Potential energy
b) Kinetic energy
c) Internal energy
d) None of the mentioned
Answer
Answer: c [Reason:] Internal energy represents a microscopic account of all the molecular, atomic, and subatomic energies.
2. Specific internal energy is a path variable. The statement is
a) True
b) False
c) Always true
d) None of the mentioned
Answer
Answer: b [Reason:] Specific internal energy is a state variable.
3. Specific internal energy _________ stored.
a) can be
b) can not be
c) may be
d) may not be
Answer
Answer: [Reason:] Specific internal energy can be stored.
4. Internal energy is the function of
a) Temperature and Pressure
b) Temperature and Volume
c) Pressure and Volume
d) None of the mentioned
Answer
Answer: b [Reason:] U = f(T,V).
5. Cv is the change in internal energy at constant _______________
a) Pressure
b) Temperature
c) Volume
d) None of the mentioned
Answer
Answer: c [Reason:] Cv is the change in internal energy at constant Volume.
6. Absolute values of internal energies ________ calculated.
a) can be
b) can not be
c) may be
d) may not be
Answer
Answer: a [Reason:] Internal energies can be calculated relative to a reference state.
7. What is the change in internal energy when 10 kg mol of Oxygen is heated from 200 K to 400 K at constant volume (Cv = 4000 J/(Degree Celsius)(Kg.mole))?
a) 2 MJ
b) 4 MJ
c) 6 MJ
d) 8 MJ
Answer
Answer: d [Reason:] U2 – U1 = n*Cv*(T2-T1).
8. Which one is true for internal energy?
a) It is sum of all forms of energies associated with molecules of a system
b) It is a state function of a system
c) It is proportional to transnational K.E of the molecules
d) All of the mentioned
Answer
Answer: d [Reason:] All are correct for internal energy and are part of its property.
9. Internal energy is a
a) Path variable
b) State variable
c) Neither path nor a state variable
d) None of the mentioned
Answer
Answer: b [Reason:] Internal energy does not depend on path.
10. A mass of 20 Kg mol is cooled from 200 K to 100 K and the change in internal energy is 400 KJ. What is the heat capacity at constant volume?
a) 100 J/(Degree Celsius)(Kg mole)
b) 200 J/(Degree Celsius)(Kg mole)
c) 300 J/(Degree Celsius)(Kg mole)
d) 400 J/(Degree Celsius)(Kg mole)
Answer
Answer: b [Reason:] U2 – U1 = n*Cv*(T2-T1).
Set 4
1. Energy a system possesses because of its velocity relative to the surrounding is
a) Kinetic Energy
b) Potential Energy
c) Work
d) None of the mentioned
Answer
Answer: a [Reason:] Energy a system possesses because of its velocity relative to the surrounding is Kinetic Energy.
2. A system is at rest, the kinetic energy of the system is
a) Infinite
b) Greater than zero
c) Less than zero
d) Zero
Answer
Answer: a [Reason:] A resting body have no velocity and kinetic energy.
3. A 5 Kg body is having a Kinetic energy of 250 J. What is the velocity of the body?
a) 10 m/s
b) 15 m/s
c) 20 m/s
d) 40 m/s
Answer
Answer: a [Reason:] K.E. = mv2/2 .
4. What is the specific kinetic energy of a particle, having a velocity 5 m/s?
a) 12.5 J
b) 25 J
c) 50 J
d) 100 J
Answer
Answer: a [Reason:] Specific Kinetic Energy = v2/2.
5. What is the unit of Specific kinetic energy?
a) J
b) J/kg
c) Pa
d) N
Answer
Answer: b [Reason:] Specific kinetic energy is kinetic energy unit mass, Unit is J/Kg.
6. Water is pumped from a storage tank through a tube of 4 cm inner diameter at the rate of 0.002 m3/sec. What is the specific kinetic energy of the water in the tube?
a) 0.26 J/Kg
b) 1.26 J/Kg
c) 2.26 J/Kg
d) None of the mentioned
Answer
Answer: b [Reason:] Specific Kinetic Energy = v2/2, v = Flow rate*Area of the tube.
7. Energy a system possesses because of the force exerted on its mass by a gravitational or electromagnetic field with respect to a reference surface.
a) Kinetic Energy
b) Potential Energy
c) Work
d) None of the mentioned
Answer
Answer: b [Reason:] Potential energy is the Energy a system possesses because of the force exerted on its mass by a gravitational or electromagnetic field with respect to a reference surface.
8. Specific Potential energy is
a) mgh
b) gh
c) h
d) None of the mentioned
Answer
Answer: b [Reason:] Specific potential energy = gh.
9. A mass is at 30 m of height from its reference point. What is the specific potential energy of the mass?
a) 294
b) 394
c) 495
d) 594
Answer
Answer: a [Reason:] Specific potential is the potential energy of the unit mass.
10. What is the potential energy of a 2 kg mass having a height of 40 m from its reference point.
a) 287
b) 784
c) 487
d) 847
Answer
Answer: b [Reason:] PE = mgh.
Set 5
1-7. For the given reaction
C5H12 + 8 O2 → 5 CO2 + 6 H2O
If the reactants C5H12 & O2 are having 2 moles an 8 moles of initial feed respectively.
1. Which is the excess reactant in the reaction?
a) C5H12
b) O2
c) CO2
d) H2O
Answer
Answer: a [Reason:] C5H12 is the excess reactant as 1 mole of C5H12 = 8 moles of CO2.
2. Which is the limiting reactant in the reaction?
a) C5H12
b) O2
c) CO2
d) H2O
Answer
Answer: b [Reason:] O2 is the limiting reactant as 1 mole of C5H12 = 8 moles of CO2.
3. How many moles of C5H12 are there when the reaction completes?
a) 0
b) 1
c) 2
d) 3
Answer
Answer: b [Reason:] Moles left = Initial mole – extent of the reaction*stoichiometric coefficient.
4. How many moles of O2 are there when the reaction completes?
a) 0
b) 2
c) 4
d) 6
Answer
Answer: a [Reason:] Moles left = Initial mole – extent of the reaction*stoichiometric coefficient.
5. How many moles of CO2 produced in the reaction?
a) 5
b) 6
c) 7
d) 8
Answer
Answer: a [Reason:] Moles produced = extent of the reaction*Stoichiometric coefficient.
6. How many moles of H2O produced in the reaction?
a) 5
b) 6
c) 7
d) 8
Answer
Answer: b [Reason:] Moles produced = extent of the reaction*Stoichiometric coefficient.
7. What is the extent of the reaction?
a) 0
b) 1
c) 2
d) 3
Answer
Answer: b [Reason:] Extent of the reaction = (Initial moles – Final moles) / Stoichiometric coefficient.
8-10. For the given reaction
CO2 + 4 H → CH2O + H2O
In the feed there are 4 moles of CO2, 10 moles of H. If the reaction happens then
8. What is the number of moles of the extent reactant in the reaction after completion?
a) 0
b) 1
c) 1.5
d) 2.5
Answer
Answer: c [Reason:] Number of moles of CO2 left = 4 – 2.5 = 1.5.
9. What is the extent of the reaction?
a) 0
b) 1
c) 1.5
d) 2.5
Answer
Answer: d [Reason:] Extent of the reaction = (Initial moles – Final moles) / Stoichiometric coefficient.
10. What is the gms of CO2 produced in the reaction?
a) 0
b) 1
c) 1.5
d) 2.5
Answer
Answer: d [Reason:] Moles of CO2 produced = 2.5 = Extent of the reaction.