Pasco TD-8564 THERMAL EFFICIENCY APPARATUS Manuel d'utilisateur télécharger pdf (Page 30)

Thermal Efficiency Apparatus 012-05443A

Experiment 2: Heat Engine Efficiency (Detailed Study)

Notes on Setup

➁ It may be necessary to prime the pump by sucking

on the output line briefly.

Sample Data

Mode T

(°C) T

(°C) V

Engine 57.9 3.5 10.00 2.02 0.890

Open 57.9 3.3 8.99 1.815 1.495

Calculated Values

Mode T

(K) T

(K) P

Engine 330.9 276.5 20.2 0.40 0.45

Open 330.9 276.3 16.3

Internal Resistance: r = 1.36Ω

Results

Actual Adjusted Maximum

(Carnot)

% Difference

Efficiency 1.96% 17.13% 16.44% -4.23%

Note that these results were obtained using slightly

lower initial voltage than recommended in the lab.

In general, mid-range temperatures give better

results than extremely large or small temperature

differences.

Answers to Questions

➀ If the temperature difference was decreased, the ef-

ficiency would also decrease.

➁ See experiment 1, question 5.

➂ For the hot reservoir, ∆S/∆t was -0.061. For the

cold reservoir, it was 0.073. The total change in en-

tropy is positive. In any non-reversible process, the

entropy will increase.

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Pasco TD-8564 THERMAL EFFICIENCY APPARATUS Manuel d'utilisateur Page 30