Chemical Engineering MCQs

Three solid objects of the same material and of equal mass-a sphere, a cylinder (length = diameter) and a cube are at 500°C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change in temperature is the smallest for

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Cube
Cylinder
Sphere
Equal for all the three
✅ The correct answer is option A.

Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer can not take place

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Between two bodies in physical contact with each other
Between two bodies not in physical contact with each other
From one part of a body to the another part of the same body
Both B & C
✅ The correct answer is option B.