Chemical Heat Transfer MCQs

Option A: Tube side pressure drop and the heat transfer rate

Option B: Convective heat transfer co-efficient

Option C: Effective tube surface area for convective heat transfer

Option D: All A. B. and C.

Correct Answer: D. All A. B. and C. ✔

Option A: 0.5

Option B: 2

Option C: 10

Option D: 100

Correct Answer: 2 ✔

Option A: Temperature gradient

Option B: Mechanical strength of the equipment

Option C: Heat transfer area

Option D: Heat transfer co-efficient

Correct Answer: Heat transfer area ✔

Option A: Pool

Option B: Nucleate

Option C: Transition

Option D: Film

Correct Answer: Film ✔

Option A: 77.2

Option B: 71.2

Option C: 63.8

Option D: 48.7

Correct Answer: 48.7 ✔

Option A: Foaming

Option B: Viscous

Option C: Very thin

Option D: Corrosive

Correct Answer: Viscous ✔

Option A: Monochromatic radiation only

Option B: Total radiation only

Option C: Both A. and B.

Option D: Only volumes and not to surfaces

Correct Answer: C. Both A. and B. ✔

Option A: Low Reynold’s number

Option B: Very low Grashoff number

Option C: Molten metals

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: 11.2 kW/m2

Option B: 12.0 kW/m2

Option C: 14.6 kW/m2

Option D: 16.5 kW/m2

Correct Answer: 16.5 kW/m2 ✔

Option A: 125

Option B: 133

Option C: 150

Option D: 160

Correct Answer: 160 ✔

Option A: Re, Pr

Option B: Re, Gr

Option C: Mainly Gr

Option D: Re only

Correct Answer: Re, Pr ✔

Option A: Capacity

Option B: Economy

Option C: Steam load

Option D: None of these

Correct Answer: Capacity ✔

Option A: m2°K/W

Option B: W/m2°K

Option C: m2°K

Option D: m°K/W

Correct Answer: m2°K/W ✔

Option A: 1

Option B: 7

Option C: 18

Option D: 26

Correct Answer: 7 ✔

Option A: Δt1/2

Option B: Δt2

Option C: Δt5/4

Option D: Δt

Correct Answer: Δt5/4 ✔

Option A: Momentum diffusivity to mass diffusivity

Option B: Momentum diffusivity to thermal diffusivity

Option C: Thermal diffusivity to mass diffusivity

Option D: Thermal diffusivity to momentum diffusivity

Correct Answer: Momentum diffusivity to thermal diffusivity ✔

Option A: CP μ/a

Option B: hD/k

Option C: CP μ/k

Option D: μ/h CP

Correct Answer: CP μ/k ✔

Option A: Steam

Option B: Condensate

Option C: Non-condensable

Option D: None of these

Correct Answer: Condensate ✔

Option A: Stefan’s

Option B: Dalton’s

Option C: Wien’s

Option D: Kirchoff’s

Correct Answer: C. Wien’s ✔

Option A: Heat balance consideration

Option B: Rate of heat transfer

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: Heat balance consideration ✔

Option A: 6

Option B: 12

Option C: 18

Option D: 24

Correct Answer: 12 ✔

Option A: Asymptotic

Option B: Hyperbolic

Option C: Parabolic

Option D: Linear

Correct Answer: Linear ✔

Option A: 1

Option B: 10

Option C: 20

Option D: 30

Correct Answer: 1 ✔

Option A: Yellow paint

Option B: White paint

Option C: Black paint

Option D: Grey paint

Correct Answer: Black paint ✔

Option A: 40

Option B: 95

Option C: 70

Option D: 50

Correct Answer: 70 ✔

Option A: Black painted bodies only

Option B: All bodies

Option C: Polished bodies only

Option D: A black body

Correct Answer: All bodies ✔

Option A: Saving of steam

Option B: Realisation of multiple effect economy in a single effect

Option C: Both A. and B.

Option D: None of these

Correct Answer: C. Both A. and B. ✔

Option A: Rate of heat transfer

Option B: Flow velocity

Option C: Turbulence of shell side fluid

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: A red hot steel slab (having outside surface temperature as 1300°C) exposed to the

Option B: 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe

Option C: Boiling brine kept in open vessel when the bottom surface temperature of the vessel is

Option D: A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper

Correct Answer: B. 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe
exposed to atmospheric air at 35°C ✔

Option A: Conduction

Option B: Natural convection

Option C: Forced convection

Option D: Radiation

Correct Answer: Radiation ✔

Option A: Temperature gradient of the wall to that across the entire pipe

Option B: Temperature difference to the temperature gradient at the wall

Option C: Heat flux at the wall to that across the entire pipe

Option D: None of these

Correct Answer: Heat flux at the wall to that across the entire pipe ✔

Option A: Thermal diffusivity/Momentum diffusivity

Option B: Thermal diffusivity × Momentum

Option C: Thermal diffusivity × Mass diffusivity

Option D: Mass diffusivity × Momentum diffusivity

Correct Answer: Thermal diffusivity/Momentum diffusivity ✔

Option A: 1

Option B: > 1

Option C: < 1

Option D: Between 1 & 2

Correct Answer: 1 ✔

Option A: Decreases

Option B: Increases

Option C: Remains unchanged

Option D: May increase or decrease; depends on the gas

Correct Answer: Increases ✔

Option A: εx + εy

Option B: εx . εy

Option C: 1/εx + 1/εy

Option D: (εx + εy)/( εx + εy – εx . εy)

Correct Answer: εx + εy ✔

Option A: Increases

Option B: Decreases

Option C: Remain same

Option D: May increase or decrease depending on the type of gas

Correct Answer: Increases ✔

Option A: Logarithmic mean area

Option B: Arithmetic mean area

Option C: Geometric mean area

Option D: None of these

Correct Answer: Logarithmic mean area ✔

Option A: Wavelength of radiation

Option B: Surface temperature of the body

Option C: Nature of the surface

Option D: Shape and porosity of the body

Correct Answer: Shape and porosity of the body ✔

Option A: Loosing sensible heat

Option B: Heat transfer to surroundings

Option C: Vaporisation due to heat loss to air

Option D: Loosing latent heat

Correct Answer: Loosing sensible heat ✔

Option A: Constant overall heat transfer co-efficient.

Option B: Constant rate of fluid flow

Option C: Constant specific heat

Option D: No partial phase change in the system

Correct Answer: Constant rate of fluid flow ✔

Option A: (r1 – r2)/ln(r1/r2)

Option B: (r1 – r2)/ln(r2/r1)

Option C: (r2 – r1)/ln(r1/r2)

Option D: (r1 – r2)/-ln(r1/r2)

Correct Answer: A. (r1 – r2)/ln(r1/r2) ✔

Option A: 2.36

Option B: 4.36

Option C: 120.36

Option D: Dependent on NRe only

Correct Answer: 4.36 ✔

Option A: Average

Option B: Geometric mean

Option C: Product

Option D: Sum

Correct Answer: Sum ✔

Option A: n = 0.4 is used for heating

Option B: n = 0.3 is used for cooling

Option C: Reynolds number for the flow involved is > 10000

Option D: Reynolds number for the flow involved is < 2100

Correct Answer: Reynolds number for the flow involved is < 2100 ✔

Option A: Increase pressure

Option B: Increase temperature

Option C: Remove condensate

Option D: None of these

Correct Answer: None of these ✔

Option A: 2000

Option B: 4000

Option C: 5000

Option D: 6000

Correct Answer: 5000 ✔

Option A: Pe = Re.Pr

Option B: Pe = Re/Pr

Option C: Pe = Pr/Re

Option D: Pe = Nu.Re

Correct Answer: Pe = Re.Pr ✔

Option A: Heat transfer co-efficient

Option B: Thermal diffusivity

Option C: Thermal conductivity

Option D: Stefan-Boltzmann constant

Correct Answer: Thermal conductivity ✔

Option A: Free convection

Option B: Entry length problem in laminar forced conduction (developing thermal boundary layer)

Option C: Mixed convection (both free and forced)

Option D: Forced convection

Correct Answer: Mixed convection (both free and forced) ✔

Option A: J.m-2.K-1

Option B: J.m-1.K-1

Option C: W.m-2.K-1

Option D: W-1m2K

Correct Answer: W-1m2K ✔

Option A: Increased

Option B: Decreased

Option C: No effect on

Option D: None of these

Correct Answer: Increased ✔

Option A: Temperature of the heating surface is less than the boiling point of the liquid

Option B: Temperature of the heating surface is more than the boiling point of the liquid

Option C: Bubbles from heating surface are absorbed by the mass of the liquid

Option D: Very large vapour space is necessary

Correct Answer: Temperature of the heating surface is more than the boiling point of the liquid ✔

Option A: Between two bodies in physical contact with each other

Option B: Between two bodies not in physical contact with each other

Option C: From one part of a body to the another part of the same body

Option D: Both B & C

Correct Answer: Between two bodies not in physical contact with each other ✔

Option A: Condensation rate

Option B: Surface configuration

Option C: Liquid flow rate from the surface

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Greater than

Option B: Lower than

Option C: Is same as

Option D: Half

Correct Answer: Lower than ✔

Option A: 1

Option B: < 1

Option C: > 1

Option D: Between 0 and 1

Correct Answer: 1 ✔

Option A: Viscosity of liquid is highest in first effect

Option B: Transfer from effect to effect is done by pumps

Option C: No pump is required to withdraw the product from the last effect

Option D: None of these

Correct Answer: None of these ✔

Option A: Glazed

Option B: Oily

Option C: Coated

Option D: Smooth

Correct Answer: Oily ✔

Option A: Corrosiveness & fouling characteristics

Option B: Pressure

Option C: Viscosity

Option D: Density

Correct Answer: Density ✔

Option A: 3.06 × 105

Option B: 6.12 × 105

Option C: 7.24 × 105

Option D: 9.08 × 105

Correct Answer: 3.06 × 105 ✔

Option A: A higher capacity

Option B: A lower capacity

Option C: Lower economy

Option D: None of these

Correct Answer: A higher capacity ✔

Option A: Mass transfer between a gas and a liquid

Option B: Absorption with chemical reaction

Option C: Heat transfer in turbulent flow

Option D: Heat transfer in laminar flow

Correct Answer: Heat transfer in laminar flow ✔

Option A: W/m

Option B: W/m2

Option C: W/°K

Option D: W/m°K

Correct Answer: W/°K ✔

Option A: Molten sodium (a coolant used in fast breeder reactor)

Option B: Water

Option C: Transformer oil

Option D: Dilute H2SO4

Correct Answer: Molten sodium (a coolant used in fast breeder reactor) ✔

Option A: Is inversely proportional to the resistance across which the drop occurs

Option B: And the wall are proportional to individual resistances

Option C: And the wall is not related

Option D: None of these

Correct Answer: And the wall are proportional to individual resistances ✔

Option A: Solution has an elevation of boiling point

Option B: Evaporators operate under vacuum

Option C: Evaporators operate at atmospheric pressure

Option D: None of these

Correct Answer: Solution has an elevation of boiling point ✔

Option A: Grashoff

Option B: Biot

Option C: Stanton

Option D: Reynolds

Correct Answer: Grashoff ✔

Option A: 0°K

Option B: 0°C

Option C: 100°C

Option D: Room temperature

Correct Answer: 0°K ✔

Option A: Nusselt number

Option B: Sherwood number

Option C: Schmidt number

Option D: Stanton number

Correct Answer: Schmidt number ✔

Option A: Conduction

Option B: Convection

Option C: Radiation

Option D: All A., B. & C.

Correct Answer: D. All A., B. & C. ✔

Option A: Volume to surface area

Option B: Perimeter to surface area

Option C: Surface area to volume

Option D: Surface area to perimeter

Correct Answer: Volume to surface area ✔

Option A: Boiling point

Option B: Dynamic viscosity

Option C: Kinematic viscosity

Option D: Density

Correct Answer: Boiling point ✔

Option A: t4

Option B: T4

Option C: 1/t4

Option D: 1/T4

Correct Answer: T4 ✔

Option A: Colburn

Option B: Reynolds

Option C: Prandtl

Option D: None of these

Correct Answer: Colburn ✔

Option A: 0.38-0.78

Option B: 0.5-50

Option C: 100-1000

Option D: 5-50

Correct Answer: 0.5-50 ✔

Option A: Boiling point (at the same pressure)

Option B: Viscosity

Option C: Density

Option D: Thermal conductivity

Correct Answer: Boiling point (at the same pressure) ✔

Option A: 0.001

Option B: 0.72

Option C: 70

Option D: 150

Correct Answer: 0.72 ✔

Option A: Less corrosion problems

Option B: Flexibility possible in the baffle arrangement

Option C: Low pressure drop

Option D: High heat transfer co-efficient

Correct Answer: Flexibility possible in the baffle arrangement ✔

Option A: Increase the heating load

Option B: Impart structural strength

Option C: Account for the uneven expansion of shell and tube bundles

Option D: Facilitate increase of shell length, if needed

Correct Answer: Account for the uneven expansion of shell and tube bundles ✔

Option A: Because of simplicity of fabrication

Option B: For low heat load

Option C: To obtain higher heat transfer co-efficient and shorter tube

Option D: To reduce the pressure drop

Correct Answer: To obtain higher heat transfer co-efficient and shorter tube ✔

Option A: > 0.75

Option B: < 0.75

Option C: < 0.50

Option D: < 0.25

Correct Answer: < 0.75 ✔

Option A: Give larger area per tube

Option B: Use metal fins of low thermal conductivity

Option C: Facilitate very large temperature drop through tube wall

Option D: Are used for smaller heat load

Correct Answer: Give larger area per tube ✔

Option A: Long tube

Option B: Falling film

Option C: High pressure

Option D: None of these

Correct Answer: Falling film ✔

Option A: D-1.8

Option B: D-0.2

Option C: D0.2

Option D: D1.8

Correct Answer: D-0.2 ✔

Option A: Arithmetic

Option B: Logarithmic

Option C: Geometric

Option D: Either A. or C.

Correct Answer: Logarithmic ✔

Option A: Tube layout

Option B: Tube diameter

Option C: Tube pitch

Option D: Number of baffles

Correct Answer: Tube diameter ✔

Option A: Parallel

Option B: Mixed

Option C: Counter flow

Option D: Same in either A , B. or C.

Correct Answer: D. Same in either A , B. or C. ✔

Option A: Supersaturated

Option B: Saturated

Option C: Wet

Option D: None of these

Correct Answer: Saturated ✔

Option A: More

Option B: Less

Option C: Some

Option D: Either more or less; depends on the nature of vapor

Correct Answer: Some ✔

Option A: Iron

Option B: Coal

Option C: Nitrogen

Option D: Tar

Correct Answer: Iron ✔

Option A: Has the unit m2 /sec

Option B: Is defined as K/ρ . Cp

Option C: Is the ratio of thermal conductivity to thermal capacity

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Temperature difference

Option B: Heat flux

Option C: That across the entire pipe

Option D: None of these

Correct Answer: That across the entire pipe ✔

Option A: Kcal/hr. m2 °C

Option B: Kcal/hr.m.°C

Option C: Kcal/hr.m

Option D: Kcal/hr. °C

Correct Answer: Kcal/hr.m.°C ✔

Option A: Both the tube sheets fixed

Option B: Both the tube sheets floating

Option C: The top tube sheet floating and bottom tube sheet fixed

Option D: The top tube sheet fixed and the bottom tube-sheet floating

Correct Answer: Both the tube sheets fixed ✔

Option A: 0

Option B: 1

Option C: 0.5

Option D: 0.90

Correct Answer: 1 ✔

Option A: Watt/m.°K

Option B: Watt/m2. °K

Option C: Watt/m2. °K

Option D: Watt/m4. °K

Correct Answer: Watt/m.°K ✔

Option A: Conduction only

Option B: Forced convection only

Option C: Forced convection and conduction

Option D: Free and forced convection

Correct Answer: Forced convection and conduction ✔

Option A: Thermal conductivity

Option B: Thickness

Option C: Temperature difference

Option D: Heat transfer area

Correct Answer: Thickness ✔

Option A: Increase

Option B: Decrease

Option C: Remain unchanged

Option D: Either increase or decrease; depends on the coolant flow rate

Correct Answer: Remain unchanged ✔

Option A: Planck’s law

Option B: Kirchhoff’s law

Option C: Wien’s law

Option D: Stefan-Boltzmann law

Correct Answer: A. Planck’s law ✔