A. m2°K/W
B. W/m2°K
C. m2°K
D. m°K/W
Related Mcqs:
- Fouling factor for a heat exchanger is given by (where, U1 = heat transfer co-efficient of dirty surface U2 = heat transfer co-efficient of clean surface) ?
A. U1 – U2
B. 1/U1 – 1/U2
C. 1/U2 – 1/U1
D. U2 – U1 - The overall heat transfer co-efficient for a shell and tube heat exchanger for clean surfaces is U0 = 400 W/m2.K. The fouling factor after one year of operation is found to be hd0 = 2000 W/m2.K. The overall heat transfer co-efficient at this time is _____________________?
A. 1200 W/m2.K
B. 894 W/m2.K
C. 333 W/m2.K
D. 287 W/m2.K - ‘Fouling factor’ used in the design of a multipass shell and tube heat exchanger is a_____________________?
A. Non-dimensional factor
B. Factor of safety
C. Conversion factor for individual film heat transfer co-efficient to overall heat transfer coefficient
D. None of these - Which is the best tube arrangement (in a shell and tube heat exchanger) if the fluids are clean and non-fouling ?
A. Square pitch
B. Triangular pitch
C. Diagonal square pitch
D. None of these - Fouling factor_____________________?
A. Is a dimensionless quantity
B. Does not provide a safety factor for design
C. Accounts for additional resistances to heat flow
D. None of these - In SI units, thermal conductivity is expressed in__________________?
A. Watt/m.°K
B. Watt/m2. °K
C. Watt/m2. °K
D. Watt/m4. °K - LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is __________________?
A. 0
B. 1
C. > 1
D. < 1 - All analogy equations connecting friction factor and heat transfer co-efficient apply only to ___________________?
A. Wall or skin friction
B. Form friction
C. Both A. and B.
D. Turbulent flow - Which of the following is the most controlling factor for the rate of bubble detachment from the hot solid surface ?
A. Liquid density
B. Liquid viscosity
C. Hot surface temperature
D. Interfacial tension - jH factor for heat transfer is not a function of the _______________ number?
A. Reynolds
B. Nusselt
C. Grashoff
D. Both B. & C.
