Total emissivity of polished silver compared to black body is___________________?

Question: For a counter current heat exchanger with Tih = 80°C, T°c = 60°C, T°h = 50°C and Tic = 30°C, and the temperature difference between the two streams being the same everywhere along Z, the direction of flow of hot fluid. The temperature profile should satisfy
[A].

[B].

[C].

[D].

Answer: Option B

Explanation:

No answer description available for this question.

Question: In a shell and tube heat exchanger, the shell side fluid velocity can not be changed by changing the
[A].

tube layout

[B].

tube diameter

[C].

tube pitch

[D].

no. of baffles

Answer: Option B

Explanation:

No answer description available for this question.

Question: Absorptivity and refletivity of a perfect black body are respectively
[A].

1 and 0

[B].

0 and 1

[C].

1 and ∞

[D].

0 and 0.5

Answer: Option A

Explanation:

No answer description available for this question.

Question: Economy of an evaporator is influenced by the
[A].

steam pressure

[B].

feed temperature

[C].

number of effect

[D].

both(b) & (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be
[A].

less than 45°C

[B].

more than 45°C

[C].

equal to 45°C

[D].

initially decreases and remains constant thereafter.

Answer: Option B

Explanation:

No answer description available for this question.

Question: While the total emissivity of a perfect black body is unity, the same for a real body is
[A].

0

[B].

1

[C].

> 1

[D].

between 0 and 1

Answer: Option D

Explanation:

No answer description available for this question.