In SI units, thermal conductivity is expressed in
(A) Watt/m.°K
(B) Watt/m2
. °K
(C) Watt/m2
. °K
(D) Watt/m4
. °K

1 Answer

Answer :

(A) Watt/m.°K

Related questions

Description : The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k

Last Answer : (C) W/m.k

Description : The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K = 0.04 W/m.°K and thickness 0.16m is 10 W/m2 . The temperature of the inside wall is - 5°C. The outside wall temperature is (A) 25°C (B) 30°C (C) 35°C (D) 40°C

Last Answer : (C) 35°C

Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Last Answer : (A) 2

Description : The unit of conductance in SI unit is (A) W/m (B) W/m2 (C) W/°K (D) W/m°K

Last Answer : (C) W/°K

Description : The units of moment of inertia are a.kgm4 b.kg-m2 c.kg/m2 d.kg/m e.m4

Last Answer : c. kg/m2

Description : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube

Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K

Description : A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of ... and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5

Last Answer : (B) 0.1

Description : Pick out the wrong statement. (A) Reciprocal of the resistance to heat flow is called thermal conductance (B) Unit of thermal conductance is W/°K (C) Thermal conductance of a wall of thickness 'L', thermal conductivity 'k' and heat flow area 'A' is kL/A (D) None of these

Last Answer : (C) Thermal conductance of a wall of thickness 'L', thermal conductivity 'k' and heat flow area 'A' is kL/A

Description : A composite flat wall of a furnace is made of two materials 'A' and 'B'. The thermal conductivity of 'A' is twice of that of material 'B', while the thickness of layer of 'A' is half that of B. If the temperature ... drop (in °K) across the layer of material 'A' is (A) 125 (B) 133 (C) 150 (D) 160

Last Answer : (D) 160

Description : The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K) (A) T (B) 1/T (C) T2 (D) 1/T2

Last Answer : A) T

Description : A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035

Last Answer : (B) 0.025

Description : The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the ... temperature of the right face in °C is (A) 77.2 (B) 71.2 (C) 63.8 (D) 48.7

Last Answer : (D) 48.7

Description : What is the unit of thermal conductivity? (A) Kcal/hr. m2 °C (B) Kcal/hr.m.°C (C) Kcal/hr.m (D) Kcal/hr. °C

Last Answer : (B) Kcal/hr.m.°C

Description : S.I. unit of Magnetic flux is (1) weber (2) weber/m (3) weber/m4 (4) weber–m2 

Last Answer : weber

Description : A BTU/hr.ft. 2 °F is equal to (A) 1 kcal/hr. m2°C (B) 4.88 kcal/hr. m. 2°C (C) 1 kcal/hr. m2 .°K (D) None of these

Last Answer : (B) 4.88 kcal/hr. m. 2°C

Description : The SI units of permitivity are: (a) N.m/C2(b) C2/N.m2 (c) N.m2/C2(d) N.m/C

Last Answer : (b) C2/N.m2

Description : The unit of Torque in SI units (a) kg-m (b) kg-cm (c) N-m (d) N/m2

Last Answer : (c) N-m

Description : In fluid flow, and heat and mass transfer, one encounters (i) kinematic velocity (μ), (ii) molecular diffusivity (θ) and thermal diffusivity (α). The units of these quantities are. (A) μ , α and θ all have units of m/ ... μ has unit of m/s (D) α and θ have units of m/s, while μ has unit of m2/s

Last Answer : Option C

Description : Thermal diffusivity of a material (A) Has the unit m2 /sec (B) Is defined as K/ρ . Cp (C) Is the ratio of thermal conductivity to thermal capacity (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Oxytremorine is a selective agonist of muscarinic _______ receptors (a) M1 (b) M2 (c) M3 (d) M4

Last Answer : Ans: A

Description : The units of moment of inertia of an area are a.kg - m b.m4 c.kg - m4 d.kg - m3 e.(kg - m)2

Last Answer : b. m4

Description : Overall heat transfer co-efficient for cooling of hydrocarbons by water is about (A) 50 -100 Kcal/hr.m2 .°C (B) 50 -100 W/m2 .°K (C) 50 -100 BTU/hr. ft. 2°F (D) 1000 - 1500 BTU/hr. ft. 2°F

Last Answer : (C) 50 -100 BTU/hr. ft. 2°F

Description : In SI units, fouling factor is expressed in (A) m2°K/W (B) W/m2°K (C) m2°K (D) m°K/W

Last Answer : (A) m2°K/W

Description : 5. Unit of surface tension in S.I. unit is (A) Watt/m (B) Joule/m2 (C) Newton/m2 (D) Joule/m

Last Answer : Option B

Description : The unit of dynamic viscosity in SI unit is (A) kg/m. sec (B) N/m2 (C) m2 /sec (D) m/N. sec

Last Answer : (A) kg/m. sec

Description : SI unit for the surface tension is ____. (1) kg/m2 (2) kg/m3 (3) N/m (4) kg/m

Last Answer : (3) N/m Explanation: Surface tension is measured in force per unit length. Its SI unit is Newton per meter.

Description : SI unit of resistivity is a. ohm b. Ohm×m c. Ohm×m-1 d. Ohm×m2

Last Answer : c. Ohm×m-1

Description : Specific capacity or yield of wells, is generally expressed, as  (A) m 3  per sec  (B) m 3 /hour  (C) m 3 /hour/m2 (D) m 3 /hour/m2 /m 

Last Answer : (D) m 3 /hour/m2 /m 

Description : The value of Stefan-Boltzmann constant in SI unit is (A) 5.6697 × 10 -8W/m2 .°K4 (B) 0.1714 × 10 -8W/m2 .°K4 (C) 5.6697 × 10 -8kcal/m2 . °K4 (D) 0.1714 × 10 -8kcal/m2 . °K4

Last Answer : (A) 5.6697 × 10 -8W/m2 .°K4

Description : The value of the product of molecular weight and the gas characteristic constant for all the gases in S.I. units is  (a) 29.27 J/kmol°K  (b) 83.14J/kmol°K  (c) 848J/kmol°K  (d) All J/kmol °K  (e) 735 J/kmol °K.

Last Answer : Answer : b

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Last Answer : (B) 16 mm/s

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Last Answer : (C) 0.7

Description : Pick out the correct statement. (A) 1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F (B) In steady state heat conduction, the only property of the substance which determines the ... in the direction of temperature rise (D) In heat transfer by forced convection, Grashoff number is very important

Last Answer : (B) In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity

Description : Three materials A, B and C of equal thickness and of thermal conductivity of 20, 40 & 60 kcal/hr. m. °C respectively are joined together. The temperature outside of A and C are 30°C and 100°C respectively. The interface ... C will be at a temperature of __________ °C. (A) 40 (B) 95 (C) 70 (D) 50

Last Answer : (C) 70

Description : One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is (A) 100 (B) 900 (C) 9000 (D) 10000

Last Answer : (D) 10000

Description : The unit of energy in S.I. units is  (a) watt  (b) joule  (c) joule/s  (d) joule/m  (e) joule m.

Last Answer : Answer : b

Description : The unit of kinematic viscosity in S. I. units is (A) N-m/s (B) N-s/m2 (C) m 2 /s (D) N-m

Last Answer : Answer: Option C

Description : The unit of dynamic viscosity in S.I. units is (A) N-m/s2 (B) N-s/m2 (C) Poise (D) Stoke

Last Answer : Answer: Option B

Description : A rod 3 m long is heated from 10°C to 90°C. Find the expansion of rod. Take Young’s modulus = 1.0 x 10^5 MN/m2 and coefficient of thermal expansion = 0.000012 per degree centigrade. 1. 0.168 cm 2. 0.208 cm 3. 0.288 cm 4. 0.348 cm

Last Answer : 3. 0.288 cm

Description : What is the SI unit of frequency? (1) Newton (2) Watt (3) Farad (4) Hertz

Last Answer : (4) Hertz Explanation: The number of waves or vibrations passing through a point in one second is called Frequency. The SI (System International) Unit of Frequency is Hertz(Hz).

Description : SI unit of luminous intensity is ______. (1) lumen (2) lux (3) candela (4) watt

Last Answer : (3) candela Explanation: Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a ... the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).

Description : Which of the following is NOT an SI unit of measure? w) watt x) newton y) joule z) erg e) second

Last Answer : ANSWER: Z -- ERG

Description : Stress may be expressed in Newtons  (A) Per millimetre square (N/mm2 )  (B) Per centimetre square (N/cm2 )  (C) Per metre square (N/m2 )  (D) None of these 

Last Answer : (A) Per millimetre square (N/mm2 )

Description : What is the SI unit of conductivity ?

Last Answer : The SI unit of conductivity Siemens/m.

Description : The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2 . The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10 -8 W/m2 .K4 ) (A) 1000 (B) 727 (C) 800 (D) 1200

Last Answer : (A) 1000

Description : Power consumption during turbulent flow in agitation tank is proportional to the __________ of the liquid. (A) Viscosity (B) Thermal conductivity (C) Surface tension (D) Density

Last Answer : (D) Density

Description : Copper has very low (A) Malleability (B) Ductility (C) Tensile strength (D) Thermal & electrical conductivity

Last Answer : (C) Tensile strength

Description : Coke oven regenerators are made of __________ bricks. (A) Fire clay (B) Silica (C) Low thermal conductivity (D) High electrical conductivity

Last Answer : (A) Fire clay

Description : A bearing metal should not have (A) Enough plasticity (B) Low thermal conductivity (C) Low co-efficient of friction (D) High toughness

Last Answer : (B) Low thermal conductivity