6 Turn on the power supply and adjust the output voltage so that the ammeter

# 6 turn on the power supply and adjust the output

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6. Turn on the power supply and adjust the output voltage so that the ammeter reads approximately 1.5 amps. 7. With the voltage properly adjusted, record the measured voltage level from the voltmeter. Turn the power supply off, place the thermometer in the water through the single-hole rubber stopper, and record the initial temperature of the water. 8. Switch the power supply back on and start the stopwatch. 9. Read and record both the ammeter and voltmeter every two minutes while gently stirring the water occasionally so that the heat from the coil will not be localized at any point in the water. 10. Remove the power supply accurately recording the time. Stir the water once more and then record the final temperature of the water. Results: Table I: Time (minute) Voltage (V) Current (A) 0 7 1.5 2 7 1.5
4 7 1.5 6 7 1.5 8 7 1.5 10 7 1.5 15 7 1.5 20 7 1.5 Mass of the empty inner cup of the calorimeter m c = 59.07 g Mass of the inner cup containing water m c + m w = 307.52 g Effective mass of the water from step 4 in the procedure m' w = 250.95 g Voltage V = 7V Current I = 1.5A Power P = I*V = 10.5W (J/s) Time t = 1200 seconds

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• Spring '16