A heating element made of tungsten wire is connected to a large battery that has negligible internal resistance. When the heating element reaches 80.0°C, it consumes electrical energy at a rate of 480 W. Assume that the temperature coefficient of resistivity has the value given in Table 25.2 in the textbook and that it is constant over the temperature range in this problem. In the equation R(T) = Ro[1+a(T - To)] take To to be 20.0°C.

A heating element made of tungsten wire is connected to a large battery that has negligible internal resistance. When the heating element reaches 80.0°C, it consumes electrical energy at a rate of 480 W. Assume that the temperature coefficient of resistivity has the value given in Table 25.2 in the textbook and that it is constant over the temperature range in this problem. In the equation R(T) = Ro[1+a(T - To)] take To to be 20.0°C.

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

Similar questions

A resistance heater is placed inside a rigid insulated tank containing 0.25 kg of nitrogen for the purpose of heating the nitrogen. A current of 0.3 Amps is supplied to the heating element that has a resistance of 60 Ohms. a. Find the time required for the heater to provide 1500 Joules. b. Find the temperature rise in the nitrogen. (Use appropriate specific heat corresponding to a temperature of 300 K).
Select the correct statement for a radial conductivity exp Select one: a. The mid outer surface represent the heating area while the side surface represent the cooling area b. None of them is true c. The inner section represent the heating area and the outer section represent the cooling area d. The outer section represent the heating area and the inner section represent the cooling area
A RTD made up of platinum has a =0.00385 and has a initial resistance of 400. Find the value of resistance Rt for the following temperatures. Temperature Resistance (Rt) 270 470 1.Resistance (Rt) at Temperature 270°C = 2. Resistance (Rt) at Temperature 470°C =
2. A rod that is 1.5 m long is made up of 0.75 m copper and 0.75 m aluminum of equal cross- sectional area and joined end to end. The rod is well insulated that there is no heat loss along the sides. The copper end is at 125 °C while the aluminum end is at 25 °C. Assuming a steady-state heat conduction, find the (a) amount of heat conducted per unit time and area of the rod and (b) temperature I at the copper-aluminum interface. (katuminum 240 /s m °C and kcopper = 390 /s m°c)
A boiler furnace wall must have a heat loss no greater than 700 Btu/hr~ft2 and is madeof a material with a thermal conductivity of 0.60 Btu/hr~ft~F. The inner wall surfacetemperature is '2000°F, and the outer surface temperature is 800°F. What wall thick~ness is required?
a slab of thickness the surface kept at 375K and other at 270k find the thermal conductivity of copper if it has net flux of 1.55
5. Given below is a log-log plot of thermal conductivity (Kt) vs temperature (T) of a non-metallic electric insulator. Explain the respective variations in KT with Tin the three different regimes indicated in the figure. (b) - exp(8,/27) Slope = +3 Slope =-1 II log T log K
30_ Select the correct statement for a radial conductivity exp Select one: a. The mid outer surface represent the heating area while the side surface represent the cooling area b. None of them is true c. The outer section represent the heating area and the inner section represent the cooling area d. The inner section represent the heating area and the outer section represent the cooling area 24_ The device with highest static head loss is Select one: a. No static head loss in this experiment b. Venturi meter c. Orifice plan d. Rotameter 26_ If surface is not leveled under the center of pressure tank Select one: a. Legs of the device can be rotated to create level surface b. Items should be added under the device to create level surface c. The device has and auto leveling d. none
Calculate the nodal temperatures of four elements in the below Fig. 2. How much heat input is required to maintain T1 = 200°C?. Consider the following A = 1 m², L = 1 m, k = 10 W/m/°C :-200W T, 13 T. T, T. 200 °C 1 3 4 Q, = 500W Ø, = 0 O, = 0 Fig. 2 2.
A solid body of length L with a rectangle cross section has a temperature distribution equals to : T = (- C/k)*e^(-x)+Cx+D. K is the conductivity and it is equal to 1 W/m.k. At x= 0 the temperature is equal to 373 K. At x= L the body is well insulated. What should be the value of heat generation so that the body is in steady state: O a. B+e^(-x) O b. B*e^(x) C*e^(-x)
How are you solving the equations in step 4 to get the values for Tad, ab, ac? Especially when each equation has two unknowns.
3. The temperature dependence of the resistivity of copper and copper - nickel alloys is shown in the figure below. Explain the reason why the resistivity is increased with Ni amount. What is the residual resistivity? Explain it. t Pres C Cu-3 at.% Ni Cu-2 at.% Ni Cu-1 at.% Ni Cu