Engineering, 15.10.2020 08:01 latiamason16
A steady electrical current passes through a 1 cm thick slab of invar (k = 15 W/(m K)), a Ni-Fe alloy whose thermal expansion coefficient from 0 ºC to 230 ºC is lower than that of any other metallic material. The specimen's faces through which the current is passed have dimensions 12 cm x 50 cm, and are maintained at 30°C and 50°C. If the electrical resistivity of invar is 80 μΩ cm, what is the largest current (in A) that can be passed through the metal without the steady-state temperature exceeding 120°C anywhere?
Answers: 2
Another question on Engineering
Engineering, 03.07.2019 14:10
If the thermal strain developed in polyimide film during deposition is given as 0.0044. assume room temperature is kept at 17.3 c, and thermal coefficient of expansion for the film and the substrate are 54 x 10^-6c^-1 and 3.3 x 10^-6c^-1respectively. calculate the deposition temperature.
Answers: 3
Engineering, 04.07.2019 18:10
Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented
Answers: 2
Engineering, 04.07.2019 18:20
Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?
Answers: 3
Engineering, 04.07.2019 18:20
Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.
Answers: 2
You know the right answer?
A steady electrical current passes through a 1 cm thick slab of invar (k = 15 W/(m K)), a Ni-Fe allo...
Questions
Chemistry, 06.05.2020 21:38
Mathematics, 06.05.2020 21:38
Mathematics, 06.05.2020 21:38
History, 06.05.2020 21:38
Mathematics, 06.05.2020 21:38
Mathematics, 06.05.2020 21:38
History, 06.05.2020 21:38
