mcqs: conduction CONDUCTION 1 MARK OBJECTIVE TYPE QUESTIONS Thermal conductivity of metals increases with the (a) Increase of temperature (b) Increase of pressure (c) Decrease of temperature (d) None (Ans: c) Temperature distribution in a plane wall is (a) Parabolic (b) Linear (c) Cubic (d) None (Ans: b) Critical radius of insulation for a cylinder […]
Mcq –conduction During conduction of heat, there is a physical motion of the (a) Crystal lattice, (b) Main body, (c) Crystal lattice as well as main body, (d) None Conduction heat transfer takes place (a) In solids only, (b) In liquids only, (c) In gases only, (d) None Critical thickness insulation stands for (a) […]
mcqs: Conduction-3 Poisson’ equation in heat transfer deals with (a) Steady state of heat transfer (b) Unsteady state of heat transfer (c) Steady as well as unsteady states of heat transfer (d) None (Ans: a) Laplace equation in heat transfer deals with (a) Steady state of heat transfer (b) Unsteady state of heat transfer (c) Steady […]
mcqs: Conduction-2 Critical radius of insulation refers to (a) Minimum rate of heat transfer (b) Maximum rate of heat transfer (c) Constant rate of heat transfer (d) None (Ans: b) Critical radius of insulation for a cylinder is equal to (a) 3k/ho (b) 2k/ho (c) 1k/ho (d) None (Ans: c) Critical radius of […]
Interview Short Question Answers on Conduction and Convection Q . Define Biot number and its significance. Biot number is Bi= conductive resistance/convective resistance = hLc/ksolid Where h is convective heat transfer coefficient W/m2K Lc is the characteristic length= volume/surface area =δ/2 for a plane wall, =r/2 for a cylinder =r/3 for a sphere = side/6 for […]
Interview Short Question Answers on Conduction and Convection-2 Q. Critical thickness of insulation. The thickness of insulation for which rate of heat transfer is maximum, is called critical thickness of insulation. Adding insulation to a wall type surface always reduces the rate of heat transfer because thermal resistance (Rth=x/KA) increases. While in case […]
Short Interview Question Answers on Unsteady state conduction Q. Discuss unsteady state conduction. When temperature varies with temperature. There are three cases of unsteady state heat conduction. 1.Heat conduction in solids of infinite conductivity or Materials with negligible internal resistance, Bi << 0.1 In this, method of analysis used is Lumped parameter Analysis. It […]
Interview Short Question Answers on Conduction-1 Q. List the basic laws which govern heat transfer. First law of thermodynamics i.e. Law of conservation of energy Second law of thermodynamics: Heat flows along negative temperature gradient. Law of conservation of mass Newton’s Law of motion The rate equations Q. What is the significance of heat […]
INTRODUCTION TO CONDUCTION Conduction is one of the three basic modes of heat transfer. The two other modes are convection and radiation. Thermal conduction takes place in solids and stationary fluids adhered to the solid surface. But the heat transfer by conduction in fluids is small because of smaller value of conductivity. Temperature difference is the […]
Interview Short Question Answers : Conduction-2 Q. Explain the significance of Fourier number. Fourier number = Fo = αt/Lc2. It signifies the degree of penetration of cooling or heating through a solid i.e. how fast heat reaches from inner face of a wall to the outer face and vice versa. It is a Non dimensional number. Q. […]