A wooden board of dimensions 30 cm x 20 cm x 20 cm is to be...
A wooden board of dimensions 30 cm x 20 cm x 20 cm is to be heated from 25°C to 175°C in 10 minutes by dielectric heating using 30 MHz supply. Parameters of wood are: Specific heat = 0.35, density = 0.5 gm/cc, relative permittivity = 5, and PF = 0.05. Determine the voltage across the specimens and current during heating. Assume loss of heat energy by radiation, convection, conduction as 5 %.
Homework Answers
Question 34 1 pts A multilayer circuit board has dimensions 4 cm by 5 cm by...
Question 34 1 pts A multilayer circuit board has dimensions 4 cm by 5 cm by 1 mm. If this board contains power and ground planes that span the entire board, and has dielectric materials with relative permittivity epsilon= 5 between these planes, what are the lowest two (nonzero) resonant frequencies of the board? 1.342 and 2.148 GHz 1.342 and 1.677 GHz 1.677 and 2.148 GHz 3.000 and 3.750 GHz Question 35 1 pts Which of the following statements regarding...
A blacksmith is flattening a steel plate having dimensions 25.7 cm x 27.7 cm. The plate...
A blacksmith is flattening a steel plate having dimensions 25.7 cm x 27.7 cm. The plate is heated to some temperature, the radiation from the plate is measured to be 816 Watts. If the emissivity of the plate is 2.00, what is the temperature of the plate? Ignore any heat exchange with the surroundings and don't worry about the thickness of the plate. (o = 5.67 x 10-8 W/m2.K4) Your answer should only have digits before the decimal.
Problem 3. A box with dimensions of 30 cm x 50 cm x 10 cm is filled with argon at 15 °C and 1 atm...
Problem 3. A box with dimensions of 30 cm x 50 cm x 10 cm is filled with argon at 15 °C and 1 atm of pressure (argon is a gas under these conditions). How much heat must be added to the argon to raise the temperature to 20 °C? (Assume the specific heat is constant over this temperature range.) You may find Table 8-1 in the text useful.
Problem 3. A box with dimensions of 30 cm x 50...
A 69-cm x 69-cm circuit board that contains 121 square chips on one side is to...
A 69-cm x 69-cm circuit board that contains 121 square chips on one side is to be cooled by combined natural convection and radiation by mounting it on a vertical surface in a room at 25°C. Each chip dissipates 0.18 W of power, and the emissivity of the chip surfaces is 0.7. Assume the heat transfer from the back side of the circuit board to be negligible, and the temperature of the surrounding surfaces to be the same as the...
Measur Questions 1. Which measurement was most precise? a) length of wooden block b) length of...
Measur Questions 1. Which measurement was most precise? a) length of wooden block b) length of cylinder e) thickness of specimen provided 2. Given: density of wood 0.8 gm/cc density of aluminum 2.70 gm/cc thickness of specimen 0.17 mm a) Determine the percent of error of the density of wood b) Determine the percent of error of the density of aluminum c) Determine the percent of error of the thickness of the specimen d) Which of these measurements was most...
QUESTION 6 Consider a 30-cm x 30-cm x 30-cm cubical body at 1000 °C suspended in...
QUESTION 6 Consider a 30-cm x 30-cm x 30-cm cubical body at 1000 °C suspended in the air. Assuming the body closely approximates a blackbody, determine the rate at which the cube emits radiation energy, i n kW 30.6 80.4 61.4 324.2 134.7 QUESTION 7 Determine the hydraulic diameter (Dh) of the duct (pipe) section shown in the following figure. (Assume: b 40 and h 20) 43.8 57.6 48.1 66.2 (8-11) Consider the arrangement of the three black surfaces shown...
Question 2 (25 %) A plate load test with plate dimensions of 20 cm x 20 cm, is performed at a con...
Question 2 (25 %) A plate load test with plate dimensions of 20 cm x 20 cm, is performed at a construction site underlain by homogeneous medium dense sand with SPT blow counts of N60 20 blows/30 cm. The plate load test results are presented in the form of load vs. settlement plot given in Figure 2. By using the plate load test results, attempt to develop the load vs. settlement plot for a mat foundation with 20 m by...
Consider a house that has a 10-m x 20-m base and a 4-m-high wall. All four...
Consider a house that has a 10-m x 20-m base and a 4-m-high wall. All four walls of the house have an R-value of 2.31m2°C/W. The two 10-m x 4-m walls have no windows. The third wall has five windows made of 0.5-cm-thick glass (k = 0.78 W/m-K), 1.2m x 1.8min size. The fourth wall has the same size and number of windows, but they are double paned with a 1.5-cm-thick stagnant air space (k = 0.026 W/m-K) enclosed between...
summatize the following info and break them into differeng key points. write them in yojr own...
summatize the following info and break them into differeng key points. write them in yojr own words
apartus
6.1 Introduction—The design of a successful hot box appa- ratus is influenced by many factors. Before beginning the design of an apparatus meeting this standard, the designer shall review the discussion on the limitations and accuracy, Section 13, discussions of the energy flows in a hot box, Annex A2, the metering box wall loss flow, Annex A3, and flanking loss, Annex...
summarizr the followung info and write them in your own words and break them into different...
summarizr the followung info and write them in your own words and break them into different key points. 6.5 Metering Chamber: 6.5.1 The minimum size of the metering box is governed by the metering area required to obtain a representative test area for the specimen (see 7.2) and for maintenance of reasonable test accuracy. For example, for specimens incorporating air spaces or stud spaces, the metering area shall span an integral number of spaces (see 5.5). The depth of...
Question 34 1 pts A multilayer circuit board has dimensions 4 cm by 5 cm by 1 mm. If this board contains power and ground planes that span the entire board, and has dielectric materials with relative permittivity epsilon= 5 between these planes, what are the lowest two (nonzero) resonant frequencies of the board? 1.342 and 2.148 GHz 1.342 and 1.677 GHz 1.677 and 2.148 GHz 3.000 and 3.750 GHz Question 35 1 pts Which of the following statements regarding...
A blacksmith is flattening a steel plate having dimensions 25.7 cm x 27.7 cm. The plate is heated to some temperature, the radiation from the plate is measured to be 816 Watts. If the emissivity of the plate is 2.00, what is the temperature of the plate? Ignore any heat exchange with the surroundings and don't worry about the thickness of the plate. (o = 5.67 x 10-8 W/m2.K4) Your answer should only have digits before the decimal.
Problem 3. A box with dimensions of 30 cm x 50 cm x 10 cm is filled with argon at 15 °C and 1 atm of pressure (argon is a gas under these conditions). How much heat must be added to the argon to raise the temperature to 20 °C? (Assume the specific heat is constant over this temperature range.) You may find Table 8-1 in the text useful.
Problem 3. A box with dimensions of 30 cm x 50...
Measur Questions 1. Which measurement was most precise? a) length of wooden block b) length of cylinder e) thickness of specimen provided 2. Given: density of wood 0.8 gm/cc density of aluminum 2.70 gm/cc thickness of specimen 0.17 mm a) Determine the percent of error of the density of wood b) Determine the percent of error of the density of aluminum c) Determine the percent of error of the thickness of the specimen d) Which of these measurements was most...
QUESTION 6 Consider a 30-cm x 30-cm x 30-cm cubical body at 1000 °C suspended in the air. Assuming the body closely approximates a blackbody, determine the rate at which the cube emits radiation energy, i n kW 30.6 80.4 61.4 324.2 134.7 QUESTION 7 Determine the hydraulic diameter (Dh) of the duct (pipe) section shown in the following figure. (Assume: b 40 and h 20) 43.8 57.6 48.1 66.2 (8-11) Consider the arrangement of the three black surfaces shown...
Question 2 (25 %) A plate load test with plate dimensions of 20 cm x 20 cm, is performed at a construction site underlain by homogeneous medium dense sand with SPT blow counts of N60 20 blows/30 cm. The plate load test results are presented in the form of load vs. settlement plot given in Figure 2. By using the plate load test results, attempt to develop the load vs. settlement plot for a mat foundation with 20 m by...
Consider a house that has a 10-m x 20-m base and a 4-m-high wall. All four walls of the house have an R-value of 2.31m2°C/W. The two 10-m x 4-m walls have no windows. The third wall has five windows made of 0.5-cm-thick glass (k = 0.78 W/m-K), 1.2m x 1.8min size. The fourth wall has the same size and number of windows, but they are double paned with a 1.5-cm-thick stagnant air space (k = 0.026 W/m-K) enclosed between...
summatize the following info and break them into differeng key points. write them in yojr own words
apartus
6.1 Introduction—The design of a successful hot box appa- ratus is influenced by many factors. Before beginning the design of an apparatus meeting this standard, the designer shall review the discussion on the limitations and accuracy, Section 13, discussions of the energy flows in a hot box, Annex A2, the metering box wall loss flow, Annex A3, and flanking loss, Annex...
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