# Aluminium foil used for cooking food and storage sometimes has one shiny surface and one dull surface. Should the shiny side or the dull side be on the outside when the food is wrapped for baking and freezing, respectively

1.  Shiny side, shiny side

2.  Dull side, dull side

3.  Shiny side, dull side

4.  Dull side, shiny side

4

Dull side, shiny side

Explanation :
No Explanation available for this question

# The temperature drop through each layer of a two-layer furnace wall is shown in the figure. Assume that the external temperatures T1 and T3 are maintained constant and that T1 > T 3. If the thicknesses of the layers, x1 and x2, are the same, which one of the following statements is correct

1.  k1 > k2, where k is the thermal conductivity of the layer

2.  k1 < k2

3.  k1 = k2, but the heat flow through material 1 is larger than that through material 2

4.  k1 = k2, but the heat flow through material 2 is less than that through material 2

4

k1 < k2

Explanation :
No Explanation available for this question

# A wire is plastically deformed (bent) by supplying a force of 40 N over a distance of 0.8 m. (The force moves in the direction in which the distance is measured). If the wire has a mass of 0.2 kg and a specific heat of 0.5 kJ/kg 0C, Estimate the maximum increase in the average temperature of the wire

1.  0.030 C

2.  0.30 C

3.  30 C

4.  300 C

4

0.30 C

Explanation :
No Explanation available for this question

# Which of the following would not increase the rate of heat transferred from a heater pipe

1.  Insulting with materials whose thickness is blow that of critical thickness for insulation

2.  Blowing air over it

3.  Providing fans

4.  Putting the heater pipe within another whose thermal conductivity is smaller in number and 2 inches thick

4

Blowing air over it

Explanation :
No Explanation available for this question

# For the situation below, what would happen to the average temperature at face C if the thermal conductivity of solid II was increased

1.  No change

2.  Becomes 200 C

3.  Increase

4.  Decrease

4

Increase

Explanation :
No Explanation available for this question

# The measure of specific heat of a material relates the quantity of heat required to change the temperature of a given mass to the mass of that material. At ordinary temperature range (or for a small temperature range) the specific heat C, may be considered constant. If aluminium has a higher specific heat (0.217 cal/gm 0C) than copper (0.093 cal/gm0C), then

1.  Copper is less massive than aluminium

2.  It takes more energy in the form of heat to change the temperature of aluminium than copper of equal mass

3.  Aluminium can be kept at a higher temperature than copper of equal mass

4.  CA/Ccu is higher at higher temperatures than lower temperatures

4

It takes more energy in the form of heat to change the temperature of aluminium than copper of equal mass

Explanation :
No Explanation available for this question

# A 10 kg solid at 1000 C with a specific heat of 0.8 kJ/kg 0C is immersed in 40 kg of 200 C liquid with a specific heat of 4.0 kJ/kg 0C. The temperature after a long time if the container is insulted will be

1.  300 C

2.  280 C

3.  260 C

4.  240 C

4

240 C

Explanation :
No Explanation available for this question

# A solid sphere and a hollow sphere of the same material and size are heated to the same temperature and allowed to cool in the same surroundings. If the temperature difference between the body and that of the surroundings is T, then

1.  Both spheres will cool at the same rate for small values of T

2.  Both spheres will cool at the same rate for all values of T

3.  The hollow sphere will cool at faster rate for all values of T

4.  The solid sphere will cool at faster rate for all the values of T

4

The solid sphere will cool at faster rate for all the values of T

Explanation :
No Explanation available for this question

# From a metallic wall at 1000 C, a metallic rod protrudes to the ambient air. The temperature at the tip will be minimum when the rod is made of

1.  Aluminium

2.  Steel

3.  Copper

4.  Silver

4

Steel

Explanation :
No Explanation available for this question

# Provision of fins on a given heat transfer surface will be more if there are

1.  Fewer numbers of thin fins

2.  Fewer numbers of thick fins

3.  Larger numbers of thin fins

4.  Larger numbers of thick fins

4