Question: Heat flux is the time rate of heat transfer per unit
[A].length
area
volume
none of these
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
No answer description available for this question.
Heat Transfer
Maximum heat transfer rate is obtained in __________ flow.
Question: Maximum heat transfer rate is obtained in __________ flow.
[A].laminar
turbulent
creeping
transition region
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
No answer description available for this question.
Peclet number (Pe) is given by
Question: Peclet number (Pe) is given by
[A].Pe = Re.Pr
Pe = Re/Pr
Pe = Pr/Re
Pe = Nu.Re
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
No answer description available for this question.
In the equation Q = UAΔt; Δt is
Question: In the equation Q = UAΔt; Δt is
[A].geometric mean temperature difference.
arithmetic mean temperature difference.
logarithmic mean temperature difference.
the difference of average bulk temperatures of hot and cold fluids.
[A].
[B].
[C].
[D].
Answer: Option C
Explanation:
No answer description available for this question.
Graetz number is given by
Question: Graetz number is given by
[A].
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
No answer description available for this question.
If h1 = inner film co-efficient and /h2 = outer film co-efficient, then the overall heat transfer co-efficient is
Question: If h1 = inner film co-efficient and /h2 = outer film co-efficient, then the overall heat transfer co-efficient is
[A].always less than h1
always between h1 and h2
always higher than h2
dependent on metal resistance
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
No answer description available for this question.
Grashhoff number is given by
Question: Grashhoff number is given by
[A].gD3.β.Δtρ2/μ2
gD2βΔtρ/μ2
gD2βΔtP2μ
gD3βΔtP2/μ
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
No answer description available for this question.
For heat flow through very thick walled cylinder, use____mean radius.
Question: For heat flow through very thick walled cylinder, use____mean radius.
[A].arithmetic
logarithmic
geometric
either (a) or (c)
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
No answer description available for this question.
Heat flux through several resistances in series in analogous to the current flowing through several
Question: Heat flux through several resistances in series in analogous to the current flowing through several
[A].resistances in parallel.
capacitors in series.
resistances in series.
none of these.
[A].
[B].
[C].
[D].
Answer: Option C
Explanation:
No answer description available for this question.
An insulator should have
Question: An insulator should have
[A].low thermal conductivity.
high thermal conductivity.
less resistance to heat flow.
a porous structure.
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
No answer description available for this question.