A hollow cylinder 10 cm internal diameter and 20 cm outer diameter ha...
Given, d
i = 10cm, d
0 = 20cm, L = 1m = 100cm
The area of the cylinder that can be used to transform a a
cylinder into an equivalent slab called Log mean area of the cylinder and it is given as
Where, Ao = πdOL = π × 20 × 100 = 2000πcm2
Ai = πdiL = π × 10 × 100 = 1000πcm2
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A hollow cylinder 10 cm internal diameter and 20 cm outer diameter ha...
To find the area of the cylinder per meter length such that it can be transformed into an equivalent slab, we need to consider the heat transfer through the cylindrical wall.
Given data:
- Internal diameter (d1) = 10 cm
- External diameter (d2) = 20 cm
- Inner surface temperature (T1) = 300°C
- Outer surface temperature (T2) = 200°C
- Thermal conductivity of cylinder material (k) = 80 W/Mk
Let's calculate the equivalent slab.
1. Calculate the thickness of the cylindrical wall:
The thickness (t) of the cylindrical wall can be calculated using the formula:
t = (d2 - d1) / 2
= (20 - 10) / 2
= 5 cm
2. Calculate the temperature difference across the cylindrical wall:
The temperature difference (ΔT) across the cylindrical wall can be calculated using:
ΔT = T2 - T1
= 200 - 300
= -100°C
3. Calculate the heat flow through the cylindrical wall:
The heat flow (Q) through the cylindrical wall can be calculated using the formula:
Q = (k * A * ΔT) / t
where A is the area of the cylindrical wall.
Rearranging the formula, we get:
A = (Q * t) / (k * ΔT)
4. Calculate the heat flow per unit length:
To find the heat flow per unit length, we need to divide the heat flow (Q) by the circumference of the cylinder.
Circumference (C) of the cylinder can be calculated using the formula:
C = π * d2
5. Calculate the area of the cylindrical wall per unit length:
The area of the cylindrical wall per unit length can be calculated using the formula:
Area per unit length = A / C
Now, let's calculate the area of the cylinder per meter length:
- Calculate the heat flow per unit length:
Q = k * A * ΔT
= 80 * A * (-100)
= -8000A
- Calculate the circumference of the cylinder:
C = π * d2
= 3.14 * 20
= 62.8 cm
- Calculate the area of the cylindrical wall per unit length:
Area per unit length = A / C
= -8000A / 62.8
Comparing the calculated equation with the given options, it can be observed that the correct answer is option 'A' (4532.36 cm2).