InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A cube `a=3.0cm` on each side radiates energy at the rate of `P=20J//s` when its temperature is `727^(@)C` and surrounding temperature `27^(@)C`. Determine its emissivity. |
|
Answer» Correct Answer - `0.066` |
|
| 2. |
Heat is conducted through a slab composed of paralel layers of two different materials of conductivities `134.4` SI units and 58.8 SI units and of thickness `3.6cm` and `4.2cm` respectively. The temperature of the outer faces of the compound slab are `96^(@)C` and `8^(@)C`. Find (i) the temperature of the interface, (ii) temperature gradient in each section of the slab. |
|
Answer» Correct Answer - `1523.8^(@)C` per metre |
|
| 3. |
One end of a copper rod of length `0.25m` and area of cross-section `10^(-4) m^(2)` is immersed in a liquid boiling at `125^(@)C` whereas the other end is kept cold by dipping It in an ice-cold bath. Find (i) temperature gradient, (ii) the rate of heat transfer (iii) the temperature at a point `0.1m` from the higher temperature end. (`lamda` of copper `=92cals^(-1)m^(-1)K^(-1)`) |
|
Answer» Correct Answer - `75^(@)C` |
|
| 4. |
A hollow cube of metal has sides measuring `0.8cm` (internal) and thickenes `0.5cm`. It is filled with ice `0^(@)C` and immersed in boiling water at `100^(@)C`. How many kg of ice will melt in one minute? Thermal conductivity of metal `=252Jm^(-1)s^(-1)K^(-1)` and latent heat capacity of ic e`=336xx10^(3)Jkg^(-1)`. |
|
Answer» Correct Answer - `34.56kg` |
|
| 5. |
A slab consists of two parallel layers of different materials `4cm` and `2cm` thick and of thermal conductivities `54cals^(-1)m^(-1)K^(-1)` and `36cals^(-1)m^(-1)K^(-1)` respectively. If the faces of the slab are at `100^(@)C` and `0^(@)C` calculate the temperature of the surface dividing the two materials. |
|
Answer» Correct Answer - `42.8^(@)C` |
|
| 6. |
Calculate the thermal resistance of an aluminium rod of length `20cm` and area of cross-section `4cm^(2)`. The thermal conductivity of aluminium is `210Js^(-1)m^(-1)K^(-1)`. |
|
Answer» Correct Answer - `2.38` SI units |
|
| 7. |
Thermal power of density `W` is generated uniformly inside a sphere of radius `R` and thermal conductivity `lamda`. Find the temperature distribution along the radius of the sphere in the steady state of it when its outer surface is at temperature `T_(0)`. |
|
Answer» Correct Answer - `T=T_(0)+((R^(2)-r^(2))W)/(6lamda)` |
|
| 8. |
A rod of length `l` with thermally insulated lateral surface is made of a material whose thermal conductivity varies as `K=sc//T` where `c` is a constant. The ends are kept at temperatures `T_(1)` and `T_(2)`. Find the temperature at a distance `x` from te first end where the temperature is `T_(1)` and the heat flow density. |
|
Answer» Correct Answer - `(T_(2))/(T_(1))` |
|