Steel Authority Of India Limited
SAIL Management Trainee
Chemical Engineering Model Papers
Q.1.Loss of heat from unlagged steam pipe to the ambient air is by- conduction
- convection
- radiation
- all (a), (b) & (c)
- convection
- radiation
- conduction
- all (a), (b) & (c)
- isothermal
- non-isothermal
- both (a) and (b)
- neither (a) and (b)
- temperature distribution is independent of time
- temperature distribution is dependent on time
- heat flows in one direction only
- three dimensional heat flow is concerned
- Kcal/hr.m2 0C
- Kcal/hr.m. 0C
- Kcal/hr.m
- Kcal/hr.0C
- BTU/hr.ft2 0F
- BTU/hr.0F.ft.
- BTU/hr.0F
- BTU/hr.ft
- Rate = Driving force * Resistance
- Driving force = Rate * Resistance
- Resistance = Driving force * Rate
- Rate = Resistance/Driving force
- low thermal conductivity
- high thermal conductivity
- less resistance to heat flow
- a porous structure
- resistances in parallel
- capacitors in series
- resistances in series
- none of these
- average
- geometric mean
- product
- sum
- Brick
- Air
- Water
- Silver
- Logarithmic mean area
- Arithmetic mean area
- Geometric mean area
- None of these
- arithmetic
- logarithmic
- geometric
- either (a) or (c)
- r1 - r2/ln r1/r2
- r1 - r2/ln r2/r1
- r2 - r1/ln r1/r2
- r1 - r2/ - ln r1/r2
- Cp.μ/k
- hD/k
- h.Cp/μ
- Cp.μ/h
- Cp.μ/a
- hD/k
- Cp.μ/k
- μ/h.Cp
- k/r.Cp
- r.Cp/k
- Cp.μ/a
- μ/hCp
- g D3. β .∆ tr2/μ2
- g D2β∆tr/μ2
- g D2β∆tr2μ
- g D3β∆tr2/μ
- always less than h1
- always between h1 and h2
- always higher than h2
- dependent on metal resistance
- mCp/kL
- kL/mCp
- mCp/kμ
- kL/mCp
- geometric mean temperature difference.
- arithmetic mean temperature difference.
- logarithmic mean temperature difference.
- the difference of average bulk temperatures of hot and cold fluids.
- Pe = Re.Pr
- Pe = Re/Pr
- Pe = Pr/Re
- Pe = Nu.Re
- Thermal diffusivity/ Momentum diffusivity
- Thermal diffusivity x Momentum
- Thermal diffusivity x Mass diffusivity
- Mass diffusivity x Momentum diffusivity
- laminar
- turbulent
- creeping
- transition region
- length
- area
- volume
- none of these
- temperature gradient of the wall to that across the entire pipe.
- temperature difference to the temperature gradient at the wall.
- heat flux at the wall to that across the entire pipe.
- none of these
- is a dimensionless quantity.
- does not provide a safety factor for design.
- accounts for additional resistances to heat flow.
- none of these.
- increase very rapidly
- increase slowly
- decrease slowly
- remain unaffected
- increasing temperature
- decreasing temperature
- decreasing Reynolds number
- none of these
- 0.5
- < 0.5
- > 0.6
- < 0.1
- buffer zone
- turbulent core
- both (a) and (b)
- viscous sub-layer
- 0.1
- > 1
- < 1
- 1
- Grashhoff number
- Peclet number
- Reynolds number
- Prandtl number
- Reynolds number
- Prandtl number
- Grashhoff number
- none of these
- Re, Pr
- Re, Gr
- mainly Gr
- Re only
- Re. Gz
- Nu, Pr
- Nu, Pr, Re
- Nu, Gz
- 1
- < 1
- > 1
- none of these
- St = f/2
- St = f/4
- St = 4f
- St = f1/2
- 1.5
- 1
- > 1
- < 1
- Liquid metal
- Aqueous solution
- Water
- Lube oil
- for fluids in laminar flow
- for fluids in tubulent flow
- when Grashhoff number is very important
- for liquid metals
- 0.06 to 120
- 0.6 to 120
- 1 to 103
- 1 to 50
- jH = (St) (Pr)2/3 = f/2
- jH = (St) (Pr)1/3 = f/2
- jH = (St)2/3 (Pr) = f/2
- jH = (St)1/3 (Pr) = f/2
- Nu = (Re) (Pr) (Gz)
- Nu = (Re) (Pr) (St)
- Nu = (Re) (Pr)
- Nu = (Pr) (St)
- Nu = 0.023 Re0.8 . Pr0.4
- Nu = p/2 Gz
- Nu = 2/p Gz
- Nu = 2Gz0.5
- ha = hl
- ha = 2 hl
- ha = 0.5 hl
- ha = 0.75 hl
- At high fluid velocity
- At low velocity
- When fluid flows past a smooth surface
- None of these
- greater than
- lower than
- is same as
- half
- momentum diffusivity to mass diffusivity
- momentum diffusivity to thermal diffusivity
- thermal diffusivity to mass diffusivity
- thermal diffusivity to momentum diffusivity
- wall or skin friction
- form friction
- both (a) and (b)
- turbulent flow