A steam pipe with outside diameter 10 mm, passes through a room, the surface temperature of the pipe is 100 °C and the air is at 25 °C. Convection coefficient is 15 W/ m2.K. The heat transfer from a tube of length 5 m is: Select one: a. 1767 W b. 1767 W/ m c. 1767 W /m2 d. 176 W e. 1765 W

A steam pipe with outside diameter 10 mm, passes through a room, the surface temperature of the pipe is 100 °C and the air is at 25 °C. Convection coefficient is 15 W/ m2.K. The heat transfer from a tube of length 5 m is: Select one: a. 1767 W b. 1767 W/ m c. 1767 W /m2 d. 176 W e. 1765 W

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

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Please solve both parts with handwriting please need with correct answer need awesome answer solve both handwriting i requested to u. Part6. An exposed 8 cm external diameter, 20 m long hot-water pipe at 80°C is losing heat to the surrounding (outdoor) air by natural convection. The average outdoor temperature is 5°C. The heat transfer coefficient is 25 W/m2°C. What is the heat loss by natural convection, in kW? A. 9.4 W B. 10.0 W C. 10.4 W D. 11.4 W Part7. A spherical ball with a diameter of 10 cm has an outer surface that is maintained at a temperature of 200°C. It is suspended in the middle of a room that has an average temperature of 20°C. If the surface emissivity is 0.8, determine the rate of radiative heat transfer from the ball to the room in W. (Choose the nearest value) A. 2.3 W B. 4.5 W C. 19.4 W D. 60.8 W
36 -S 42 2. Metal castings can sometimes develop a gap between the casting and mold as the molten metal hardens. The result can be a substantially altered cooling process. Set up a simple heat-transfer model that would let you look at the effect of the gap on the cooling process. Assume the casting and mold are square in shape, with an air gap of thickness das shown in the figure. The mold sits in some ambient room temperature. State clearly all assumptions and develop a corresponding model of the heat transfer problem. Assuming that the casting is aluminum, the mold is diatomaceous earth and the gap is filled with air, see if you can arrive at and summarize some insight into the effect of the gap and its size on the heat transfer process.
A house, for cooling purposes, consists of two zones: the atric area zone A and the living area zone B (see below figure). The living area is cooled by a 2 -ton air conditioning unit that removes 23,000 Btu/hr. The heat capacity of zone B is 1/6 °F per thousand Btu. The time constant for heat transfer between zone A and the outside is 3ℎr, between zone B and the outside is 6ℎr, and between the two zones is 6ℎr. If the outside temperature stays at 90°F, how warm does it eventually get in the attic zone A ?
2.) A 30 ft copper pipe is 1.5 ft in diameter and has a thickness of 2 in. It has an internal temperature of 85F and an external temperature of 70F. Solve for k if the rate of heat transfer is 2.6 x 106 Btu hr
: A spherical container ( k= 30 W/moC ) with inner radius r1 = 2 m and outer radius ro=2.1 m is is filled with ice water T= 0 oC subjected to the convection on the outer surface T∞2 = 25 oC , h∞2= 18 W/m2 oC .For steady one-dimensional heat transfercalculate a) The mathematical formulation b) the variation of temperature, and c) therate of heat transfer are to be determined fo
A plane wall has internal heat generation and is cooled covectively at its two faces. Given : A) heat generation ate g1,000W /m? 2L 100 mm wall thickness T- 20C air temp temp within wall T(x)=10(0.05'-x')+30 W Im.K Al) Find thermal conductivity of the wall k WIm'.K A2) Find convection heat transfer coeff
C: water flows at 50 °C inside a 2.5 cm diameter tube such that h-3500 W/m2. °C. The tube has a wall thickness of 0.8 mm with a thermal conductivity of 16 W/m.°C. The outside of the tube loses heat by convection with ho-7.6 W/m².°C. If the heat loss to the surrounding per unit length is 19 W. Calculate the surrounding air temperature.
A 25 cm thick brick wall of 4 m by 3 m has inner and outer surfaces at 15 C and 7 C, respectively. What is the value of the conductivity if the heat rate by conduction is equal to 2300 W. Select one: a. 5.99 W/m. C b. 4.71 W/m. C c. 3.84 W/m. C d. 6.9 W/m. C
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A tube having a cylindrical shape of length equals to 30 m and diameter equals to 10 cm passes through a room. If the temperature of the outer surface of the tube is 110 C and the temperature of the air in the room is 10 C. Determine the rate of heat transfer by convection from the tube to the air. The heat transfer coefficient h = 3 W/m^2.K. Select one: a. 355 W b. 43 kW c. 2827.35 W
A house, for cooling purposes, consists of two zones: the attic area zone A and the living area zone B (see below figure). The living area is cooled by a 2-ton air conditioning unit that removes °F per thousand Btu. The time constant for heat 19 4 41,000 Btu/hr. The heat capacity of zone B is transfer between zone A and the outside is 2 hr, between zone B and the outside is 4 hr, and between the two zones is 4 hr. If the outside temperature stays at 90°F, how warm does it eventually get in the attic zone A? It eventually gets to be F in the attic zone A. (Type an integer or decimal rounded to the nearest hundredth as needed.) 4 hr 쉽 A H 4 hr B 2 hr MIN 41,000 Btu/hr
1 33 2 30 6 7 8 9 13 14 17 19 20 21 22 230 11 43 24 25 34 26 38 390 400 41 42 44 45 46 49 QUESTION 1 A domestic refrigerator with inner dimensions of 0.7 m by 0.7 m at the base and height 1 m was designed to maintain a set temperature of 6 °C. The bodies consist of two 10-mm-thick layers of Aluminium (k = 225 W/mK) separated by a 30 mm polyurethane insulation (k-0.028 W/mK). If the average convection heat transfer coefficient at the inner and outer surfaces are 116 W/m²K and 14.5 W/m2K respectively, calculate the resistance(R) for the inner fluid thermal layer in K/W to 4 decimal places. 4 QUESTION 2 4 350 36 5 37 15 16 B