Q3. A small electric heating application uses wire of 2 mm diameter with 0.8 mm thick insulation (k 0.15 W/m°C). The heat transfer coefficient (ho) on the insulated surface is 31 W/M2°C. Determine the critical thickness of insulation in this case and the percentage change in the heat transfer rate if the critical thickness is used, assuming the temperature difference between the surfaces of the wire and surrounding air remains unchanged. Wire Insulator ho 0.8 mm

Q3. A small electric heating application uses wire of 2 mm diameter with 0.8 mm thick insulation (k 0.15 W/m°C). The heat transfer coefficient (ho) on the insulated surface is 31 W/M2°C. Determine the critical thickness of insulation in this case and the percentage change in the heat transfer rate if the critical thickness is used, assuming the temperature difference between the surfaces of the wire and surrounding air remains unchanged. Wire Insulator ho 0.8 mm

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Related questions

Q: A plane wall of thickness 2L = 100 mm with uniform heat generation of 700 W/m³ and a surface…

Q: h = 30 W/m²K Taj = 20°C h. = 60 W/m²K Tzo =-15°C Fiberglass L=10 cm Plaster board Plywood L=2 cm…

Q: Problems within the wall is T(x) = a(L- ) +b where a = 10°C/m2 and b 30°C, what is the thermal con-…

A: Given data as per questionAssumptionsSteady state condition.One dimensional conductionNo internal…

Q: Consider a closed cylindrical reactor vessel of diameter D= 1 ft, and length L= 1.5 ft. The surface…

Q: A very thin silicon chip is bonded to a 6-mm thick aluminum substrate by a 0.02-mm thick epoxy glue.…

Q: Heat Transfer Mechanisms 5- In a certain experiment, cylindrical samples of diameter 4 cm and length…

Q: A steam pipe, made of copper, has an inside diameter of 5 cm and an outside diameter of 6.2 cm. To…

Q: An isothermal sphere 3 cm in diameter at 80°C is embedded in a large clay region. The temperature of…

A: Disclaimer: “Since you have asked multiple questions, we will solve the first question for you i.e…

Q: An internal engine of a rocket (180°C furnace) generates heat flow of 23.2564 kW through a first…

A: ◆ This is the case of heat transfer through the cylindrical layer. ◆ The temperature profile for…

Q: 3. Hot water flows inside a 2.5 cm inner diameter tube, the tube has a wall thickness of 0.8 mm…

A: Given: Inner radius = 2.5 cm Thickness = 0.8 mm And 3 thermal resistances Correct answer: A 9.94…

Q: For one -dimension heat transfer conduction consider a shielding wall for a nuclear reactor. The…

Q: A pipe having an outside diameter of 6 cm is maintained at 200°C by steam flowing inside. The pipe…

Q: wo heat reservoirs with respective temperatures of 325 and 275 K are brought into contact by an iron…

A: Given Thermal conductivity, k = 79.5 W/m K Temperature, T1 = 325 K…

Q: vity of 0.5. Assume the specific heat to remain constant at 600 J/kgK. Use a time step of 30 seconds…

A: Build a spreadsheet to do the step by step method for estimating the temperature of unprotected…

Q: Consider a conduction in a plane composite wall as shown. The outer hotter air temperature at 60 C…

Q: Question 1 A furnace wall consisting of 0.20 m of fire clay brick. 0.15 m of kaolin, and a 0.05-m…

Q: Example 1 A 15 mm diameter and 5 m long electric wire is tightly wrapped with 2 mm thick plastic…

Q: A 2 mm diameter wire with 0.8 mm thick layer of insulation (k = 0.15 W/moC) is used in a certain…

Q: QUESTION 8 A 1m by 2m glass wool insulation wall (k=0.036 W/mK) with a thickness of 5cm has an…

Q: = 16 W/m.K. The inner diameter and thickness of the pipe are 26 cm and 1 cn espectively. The…

A: Boundary Conditions T( r1 ) = T1 =350oC T( r2 ) = T2 = 28oC dTdr=C1r T(r) = C1 lnr + C2 T( r1 ) =…

Q: An insulated pipe has an inner diameter of 0.05 m and an outer diameter of 0.06 m. If the insulation…

Q: An electronic component, 65 mmx65 mm, in steady state operation reaches the base temperature of…

Q: 1. Find the rate of heat leakage for a spherical tank 2 m inside diameter and 12 mm thick with…

Q: An oil flow through a 40 mm bore steel pipe with the thickness of 4 mm. The pipe is covered by 10 mm…

A: When heat flows from higher temperature T1 to lower temperatureT2 across the surface then, total…

Q: A room is well insulated apart from a single-glazed window measuring 1 m2 and 4 mm thick. The…

A: To find: The convective heat transfer coefficient for outside hout. Given : The Area is A=1 m2.…

Q: Q4-A furnace of 100 x 80 x 60-cm inside dimensions is constructed of a material having a thermal…

A: Given A=100×80×60 cmk=2.4 W/mKt=10cmTi=1000K=1000-273=727oCTo=20oCh=15 W/m2Co

Q: Suppose that the 10 cm thick concrete wall of a commercial building measures 30 mby 4 m. The energy…

A: The three heat transfer mechanisms are conduction, convection, and radiation.Conduction: This is the…

Q: heating cube with a size of 60 x 60 cm on the inside is made of refractory brick (k=1.04 watt/(m.°c)…

A: Given Data K=1.04 W/mK X=12 cm

Q: The thermal conductivity of a sheet of rigid, extruded insulation is reported to be k= 0.029 W/m. K.…

Q: an unsisulated 100 mm diameter steam pipe runs for 25 meters inside a room whose walls and air are…

Q: . Saturated steam at 500 K flows in a 0.20 m inside diameter, 0.21 m outside diameter pipe. The pipe…

Q: Heat is produced in a long resistance wire q.u= 1.5 W/cm3. The radius of the wire is given as r1=0.3…

Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.

Question

Q3. A small electric heating application uses wire of 2 mm diameter with 0.8 mm
thick insulation (k = 0.15 W/m°C). The heat transfer coefficient (ho) on the insulated
surface is 31 W/m2°C. Determine the critical thickness of insulation in this case and
the percentage change in the heat transfer rate if the critical thickness is used,
assuming the temperature difference between the surfaces of the wire and
surrounding air remains unchanged.
Wire
Insulator
0.8
mm

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

Step 2

Step 3

Step 4

Trending now

This is a popular solution!

Step by step

Solved in 4 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

Similar questions

Heat transfer
I need the answer as soon as possible
We have a wall (k = 10 W/mK) with a thickness of 0.4 m. At a certain instance of time temperature distribution is given by T(x) = 50 x²– 450 x + 350. a- Please calculate the rate of heat transfers entering and leaving the wall for a unit surface area and also find the change in the energy storage of the wall. b- If the environment temperature is 85 °C, what is the convection coefficient between the cold surface of the wall and environment.
Q3. A small electric heating application uses wire of 2 mm diameter with 0.8 mm thick insulation (k = 0.15 W/m°C). The heat transfer coefficient (ho) on the insulated surface is 31 W/m2°C. Determine the critical thickness of insulation in this case and the percentage change in the heat transfer rate if the critical thickness is used, assuming the temperature difference between the surfaces of the wire and surrounding air remains unchanged. - Wire Insulator air 12 0.8 mm
Homework problem for unsteady-state heat transfer Consider a product to be sterilized if its coldest location during heating reaches 115°C. Consider sterilization of potatoes where potatoes (4 cm diameter) is heated in steam at 121°C. Assume symmetrical heating of potatoes and the heat transfer coefficient between the steam and the potatoes is 20 W/m² K. The thermal diffusivity for potatoes is 1.5 × 107m²/s and the thermal conductivity is 0.4 W/m K. The potatoes are initially at 30°C. 1) Calculate the heating time needed for sterilization. 2) Calculate the temperature at the center of the potato after heating 1000 s and 2000 s. Plot how the temperature at the center changes with time t. 3) Calculate the temperature at the surface of the potato at 2000 s. Qualitatively plot how the temperature changes across the apple at t = 2000 s.
a. given convective heat transfer coefficient of inside air = 18.23 W/m2K, find the temperature of inside air at the end of composite wall b. neglect natural convection, find heat transfer rate due to thermal radiation c. using heat transfer rate due to thermal radiation, find the innermost wall and interface temperatures
Two approaches used in development of the thermal resistance network in the x-direction for multi-dimensional problems are to assume any plane wall normal to the x-axis to be isothermal and to assume any plane parallel to the x-axis to be adiabatic. True or False True False
A steel pipe with heat transfer coefficient of 42 W/mK contains flowing water. The outer diameter of the pipe is 90 mm and the wall thickness is 3mm. Calculate: i. The heat loss by convection and conduction per meter length of un-insulated pipe when the water temperature is 14°C, the outside air temperature is -10°C, the water side heat transfer coefficient is 30 KW/m^2K and the outside heat transfer coefficient is 20 KW/m^2K. ii. Calculate the corresponding heat loss when the pipe is lagged with insulation having an outer diameter of 200 mm, and thermal conductivity of K = 0.05 W/mK
Need correctly..