# Critical radius of a hollow cylinder is defined as

1.  Outer radius which gives maximum heat flow

2.  Outer radius which gives minimum heat flow

3.  Inner radius which gives minimum heat flow

4.  Inner radius which gives maximum heat flow

4

Outer radius which gives maximum heat flow

Explanation :
No Explanation available for this question

# Ratio of mass heat flow rate to the heat flow rate by conductions under a unit temperature gradient and through a thickness, it known as

1.  Reynolds number

2.  Prandtl number

3.  Place lent number

4.  Stanton number

4

Place lent number

Explanation :
No Explanation available for this question

# 1 micron is equal to

1.  10-4 meters

2.  10-6 meters

3.  10-8 meters

4.  10-12 meters

4

10-6 meters

Explanation :
No Explanation available for this question

# Heat conduction does not occur

1.  If a physical body is impermeable to any kind of rays

2.  If the parts of a body are not in motion relative to one another

3.  If the bodies are kept in vacuum

4.  If the temperature of the two bodies are identical

4

If the temperature of the two bodies are identical

Explanation :
No Explanation available for this question

# For steady flow and constant value of conductivity, the temperature distribution for a plane wall is

1.  Parabolic

2.  Linear

3.  Logarithmic

4.  Cubic

4

Linear

Explanation :
No Explanation available for this question

# The rate of heat flow through a composite wall of three layers of thickness 0.3 m, 0.2 m, 0.15 m and of corresponding thermal conductivities 1.2, 0.8 and 0.6 kJ/hr0C is 1280 kJ/hr. If the surface area normal to the direction of flow of heats is 1 m2 and inner surface temperature is 10000 C, then the interface temperature at the end of first layer will be

1.  7000 C

2.  6800 C

3.  5000 C

4.  3600 C

4

6800 C

Explanation :
No Explanation available for this question

# The highest value of thermal conductivity is expected for

1.  Solid ice

2.  Water

3.  Steam

4.  Superheated steam

4

Solid ice

Explanation :
No Explanation available for this question

# The heat transfer takes place according to

1.  Zeroth law of thermodynamics

2.  First law of thermodynamics

3.  Second law of thermodynamics

4.  Kirchhoff’s law

4

Second law of thermodynamics

Explanation :
No Explanation available for this question

# A furnace wall of thickness 1 m and of surface area 2 m2, is made of material whose thermal conductivity is 1 kJ/hr m0C. The temperature of inner surface of the wall is 10000 C and of outer surface is 2000 C. Heat flow through the wall in kJ/hr will be

1.  2000

2.  1600

3.  1200

4.  800

4

1600

Explanation :
No Explanation available for this question

# Two cars are moving in the same direction with a speed of 45km/hr and a distance of 10km separates them. If a car coming from the opposite direction meets these two cars at an interval of 6 minutes its speed would be

1.  45km/hr

2.  10m/sec

3.  √21 m/sec

4.  11m/sec

4

11m/sec

Explanation :
No Explanation available for this question

## Interview Questions

 MongoDB Java Script Node JS PHP JQuery Python