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Zorluk: OrtaTemperature Scales and Thermometric Properties

A resistance thermometer registers a resistance of 5.0 Ω5.0\,\Omega at the ice point (0∘C0^\circ\text{C}) and 25.0 Ω25.0\,\Omega at the steam point (100∘C100^\circ\text{C}). When placed in a heated liquid bath, the resistance measured is 30.0 Ω30.0\,\Omega. What is the temperature of the bath on the Kelvin scale?

  1. A
    125 K125\,\text{K}
  2. 398 K398\,\text{K}Cevap
  3. C
    423 K423\,\text{K}
  4. D
    373 K373\,\text{K}

Cevap

The temperature of the bath on the Kelvin scale is 398 K398\,\text{K}.
Using the linear interpolation formula for a thermometric property θ=Rθ−R0R100−R0×100∘C\theta = \frac{R_\theta - R_0}{R_{100} - R_0} \times 100^\circ\text{C}, substituting R0=5.0 ΩR_0 = 5.0\,\Omega, R100=25.0 ΩR_{100} = 25.0\,\Omega, and Rθ=30.0 ΩR_\theta = 30.0\,\Omega yields θ=25.020.0×100=125∘C\theta = \frac{25.0}{20.0} \times 100 = 125^\circ\text{C}. Converting to absolute thermodynamic temperature gives T=125+273=398 KT = 125 + 273 = 398\,\text{K}.

Adım Adım Çözüm

1
Calculate the temperature on the Celsius scale using linear interpolation of thermometric property.
θ=Rθ−R0R100−R0×100∘C=30.0−5.025.0−5.0×100∘C=25.020.0×100∘C=125∘C\theta = \frac{R_\theta - R_0}{R_{100} - R_0} \times 100^\circ\text{C} = \frac{30.0 - 5.0}{25.0 - 5.0} \times 100^\circ\text{C} = \frac{25.0}{20.0} \times 100^\circ\text{C} = 125^\circ\text{C}
The change in resistance is directly proportional to the temperature change between fixed points.
2
Convert the temperature from degrees Celsius to Kelvins.
T=θ+273=125+273=398 KT = \theta + 273 = 125 + 273 = 398\,\text{K}
Absolute temperature in Kelvin is obtained by adding 273 to the temperature in degrees Celsius.

Anahtar Kavram

Temperature Scale Interpolation and Kelvin Conversion
Tahmini Süre:1m 30s
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