1.0 0.83 0.50 0.17 1.90 2.80 λ(μm)
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Problem 2 (10 points) Find the emissivity at 400 K and the solar absorptivity of the diffuse material with the measured...
2.11 Find the emissivity at 950 K and the solar absorptivity of the diffuse measured spectral...
2.11 Find the emissivity at 950 K and the solar absorptivity of the diffuse measured spectral emissivity shown in the figure. This will require numerical 1.0 0.83 0.50 0.17 0 0.70 1.90 2.80 3.50 ? ( nm) Answer: ?(950 K) = 0.3248; e(5780 K) ?,(5780 K) = 0.7564.
Problem 3 (15 points) A white ceramic surface has a hemispherical spectral emissivity distribution at 1600 K as shown....
Problem 3 (15 points) A white ceramic surface has a hemispherical spectral emissivity distribution at 1600 K as shown. What is the hemispherical total emissivity of the surface at this surface temperature? My guess is you need to do a numerical integration here. 1.0 0.8 0.6 E N 0.4 0.2 10 10 2 4 6 8 10 12 λ, μ
Problem 3 (15 points) A white ceramic surface has a hemispherical spectral emissivity distribution at 1600 K as shown. What...
A small object with an opaque, diffuse surface at a temperature of 500 K is suspended...
A small object with an opaque, diffuse surface at a temperature
of 500 K is suspended in a large furnace with walls at 2000 K.
Assume that the walls of the furnace provide a diffuse irradiation
to the object at a blackbody temperature equal to the furnace wall
temperature. The object’s surface has a spectral hemispherical
emissivity and absorptivity as given below. (a) Determine the total
emissivity and total absorptivity of the object’s surface. Partial
Ans: ?=0.021 (b) Evaluate the...
Problem 3 (10 points) For a blackbody at 2250 K that is in air, find: (b) the hemispherical total emissive power (kW Im2). (c) the emissive power in the spectral range between o 2 and 8um. (d) the ra...
Problem 3 (10 points) For a blackbody at 2250 K that is in air, find: (b) the hemispherical total emissive power (kW Im2). (c) the emissive power in the spectral range between o 2 and 8um. (d) the ratio of spectral intensity at no-2 μm to that at no-8 μm.
Problem 3 (10 points) For a blackbody at 2250 K that is in air, find: (b) the hemispherical total emissive power (kW Im2). (c) the emissive power in the spectral...
Problem 5 (10 points) A gray surface has a directional emissivity isotropic with respect to circumferential angle as sh...
Problem 5 (10 points) A gray surface has a directional emissivity isotropic with respect to circumferential angle as shown in the figure. The properties are (a) What is the hemispherical emissivity of this surface? (b) If the energy from a directions, what fraction of the incident energy is absorbed by this surface? (c) If the surface is placed in a very cold environment, at what rate must energy be added per unit area to maintain the surface temperature at 1000...
Problem 5 (10 points) A gray surface has a directional emissivity isotropic with respect to circumferential angle as sh...
Problem 5 (10 points) A gray surface has a directional emissivity isotropic with respect to circumferential angle as shown in the figure. The properties are (a) What is the hemispherical emissivity of this surface? (b) If the energy from a directions, what fraction of the incident energy is absorbed by this surface? (c) If the surface is placed in a very cold environment, at what rate must energy be added per unit area to maintain the surface temperature at 1000...
2.A. (15 points) The E versus k diagrams for a free electron (curve A) and for...
2.A. (15 points) The E versus k diagrams for a free electron (curve A) and for an electron in a semiconductor (curve B) is shown in the figure on the right. Sketch dE/dk versus k and dE/dk' versus k for each curve. What conclusion can you make about the effective masses in each of the two cases? 2.B. (15 points) The Fermi energy level for a particular material at T = 350 K is 2.50 eV. The electrons in this...
[Problem 1 Information] Problem 2: 10 points Continue with the Poisson distribution for X from...
[Problem 1 Information]
Problem 2: 10 points Continue with the Poisson distribution for X from Problem 1. Find the conditional expectation of X given that X takes an even value. oution for X from Problem 1. Find Assume that a random variable X follows the Poisson distribution with intensity λ, that is for k 0,1,2, . Using the identity (valid for all real t) k! k=0 derive the probability that X takes an even value, that is PX is...
helpp Problem 5b. - 10 Points total A semiconductor material has an energy gap of 0.75...
helpp
Problem 5b. - 10 Points total A semiconductor material has an energy gap of 0.75 eV, effective masses mn= 0.04 mo and mp= 0.22 mo, where mo is the free electron mass = 9.11 x 103 [kg]. Assume complete ionization. a) Let the temperature be T = 350 °K. The material is un-doped. Find the intrinsic Fermi level EFi and carrier concentration ni- pi (4 points) b) Let the temperature be T = 350 K. The material is doped...
Problem #7 (10 points) For the feedback control system shown in figure (4), R) I. 2....
Problem #7 (10 points) For the feedback control system shown in figure (4), R) I. 2. Determine the steady state error ess when K = 1 Determine the value of K to minimize the steady state error ess R(S) (s +2) 6+5 Figure (4) Problem #8 (10 points) For the feedback control system shown in figure (5, R(s)-ine the range of K such that the absolute value of the steady state error is less than 0.1 R(S) s+K Y(S) Figure...
2.11 Find the emissivity at 950 K and the solar absorptivity of the diffuse measured spectral emissivity shown in the figure. This will require numerical 1.0 0.83 0.50 0.17 0 0.70 1.90 2.80 3.50 ? ( nm) Answer: ?(950 K) = 0.3248; e(5780 K) ?,(5780 K) = 0.7564.
Problem 3 (15 points) A white ceramic surface has a hemispherical spectral emissivity distribution at 1600 K as shown. What is the hemispherical total emissivity of the surface at this surface temperature? My guess is you need to do a numerical integration here. 1.0 0.8 0.6 E N 0.4 0.2 10 10 2 4 6 8 10 12 λ, μ
Problem 3 (15 points) A white ceramic surface has a hemispherical spectral emissivity distribution at 1600 K as shown. What...
A small object with an opaque, diffuse surface at a temperature
of 500 K is suspended in a large furnace with walls at 2000 K.
Assume that the walls of the furnace provide a diffuse irradiation
to the object at a blackbody temperature equal to the furnace wall
temperature. The object’s surface has a spectral hemispherical
emissivity and absorptivity as given below. (a) Determine the total
emissivity and total absorptivity of the object’s surface. Partial
Ans: ?=0.021 (b) Evaluate the...
Problem 3 (10 points) For a blackbody at 2250 K that is in air, find: (b) the hemispherical total emissive power (kW Im2). (c) the emissive power in the spectral range between o 2 and 8um. (d) the ratio of spectral intensity at no-2 μm to that at no-8 μm.
Problem 3 (10 points) For a blackbody at 2250 K that is in air, find: (b) the hemispherical total emissive power (kW Im2). (c) the emissive power in the spectral...
Problem 5 (10 points) A gray surface has a directional emissivity isotropic with respect to circumferential angle as shown in the figure. The properties are (a) What is the hemispherical emissivity of this surface? (b) If the energy from a directions, what fraction of the incident energy is absorbed by this surface? (c) If the surface is placed in a very cold environment, at what rate must energy be added per unit area to maintain the surface temperature at 1000...
Problem 5 (10 points) A gray surface has a directional emissivity isotropic with respect to circumferential angle as shown in the figure. The properties are (a) What is the hemispherical emissivity of this surface? (b) If the energy from a directions, what fraction of the incident energy is absorbed by this surface? (c) If the surface is placed in a very cold environment, at what rate must energy be added per unit area to maintain the surface temperature at 1000...
2.A. (15 points) The E versus k diagrams for a free electron (curve A) and for an electron in a semiconductor (curve B) is shown in the figure on the right. Sketch dE/dk versus k and dE/dk' versus k for each curve. What conclusion can you make about the effective masses in each of the two cases? 2.B. (15 points) The Fermi energy level for a particular material at T = 350 K is 2.50 eV. The electrons in this...
[Problem 1 Information]
Problem 2: 10 points Continue with the Poisson distribution for X from Problem 1. Find the conditional expectation of X given that X takes an even value. oution for X from Problem 1. Find Assume that a random variable X follows the Poisson distribution with intensity λ, that is for k 0,1,2, . Using the identity (valid for all real t) k! k=0 derive the probability that X takes an even value, that is PX is...
helpp
Problem 5b. - 10 Points total A semiconductor material has an energy gap of 0.75 eV, effective masses mn= 0.04 mo and mp= 0.22 mo, where mo is the free electron mass = 9.11 x 103 [kg]. Assume complete ionization. a) Let the temperature be T = 350 °K. The material is un-doped. Find the intrinsic Fermi level EFi and carrier concentration ni- pi (4 points) b) Let the temperature be T = 350 K. The material is doped...
Problem #7 (10 points) For the feedback control system shown in figure (4), R) I. 2. Determine the steady state error ess when K = 1 Determine the value of K to minimize the steady state error ess R(S) (s +2) 6+5 Figure (4) Problem #8 (10 points) For the feedback control system shown in figure (5, R(s)-ine the range of K such that the absolute value of the steady state error is less than 0.1 R(S) s+K Y(S) Figure...
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