MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

HT in Composite Rectangular Slabs

A furnace has...

Question

A furnace has a 10 cm thick wall with thermal conductivity 0.95 W/mK. For the same heat loss from the furnace what will be the thickness of the wall if the thermal conductivity of the material is 0.19 W/mK?

A

2 cm

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

B

4 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

10 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

40 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A 2 cm
$Q_{1} = Q_{2}$

$\frac{Δ T}{\frac{L_{1}}{k_{1} A}} = \frac{Δ T}{\frac{L_{2}}{k_{2} A}}$

$\frac{k_{1}}{L_{1}} = \frac{k_{2}}{L_{2}}$

$\frac{k_{1}}{k_{2}} = \frac{L_{1}}{L_{2}}$

$\frac{0.95}{0.19} = \frac{10}{L_{2}}$

$L_{2} = 2 c m$

Suggest Corrections

thumbs-up

0

Similar questions

Q. A furnace has a wall of 20 cm thickness with thermal conductivity k = 2 W/mK. An insulation of 3 cm is applied which has thermal conductivity of 0.008 W/mK. On the left side of the wall there is flue gas at a temperature of

700^{\circ} C

with convective heat transfer coefficient 100

W / m^{2} K

. Outside temperature of the insulation is

25^{\circ} C

. Intermediate temperature is

Q. A wall of 0.5m thickness is to be constructed from a material that has an average thermal conductivity of 1.4 W/mK. The wall is to be insulated with a material having an average thermal conductivity of 0.35 W/mK so that heat loss per square meter will not exceed 1450 W. Assuming that the inner and outer wall surface temperatures are 1200°C and 15°C respectively, the thickness of insulation required is

Q. Temperature distribution at certain instant of time across a wall of thickness 1 m is given by

T = 800 - 300 x - 50 x^{2}

. The wall has a constant heat generation of

1000 {W/m}^{3}

. Density of material is

1600 {kg/m}^{3}

, thermal conductivity is 40 W/mK and specific heat of material is 3 kJ/kgK. What will be the rate of change of internal energy of wall for per unit cross-sectional area ?

Q. Two material of thermal conductivities 5 and 10 W/k K having a thickness of 0.2 m each are used to construct a composite wall. The overall thermal conductivity of the wall is

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

HT in Composite Rectangular Slabs

OTHER

Watch in App

explore_more_icon

Explore more

HT in Composite Rectangular Slabs

Join BYJU'S Learning Program

CrossIcon