Is Nichrome Wire an Ohmic Resistor Conductor Experiment Essay Example

of this experiment. When the power source was switched on the light bulb lighted up. The readings on the ammeter and the voltmeter went up as the power input went up.

The resistance also becomes greater as the voltage and current is higher. On a low power setting the light bulb was dimmer than when it was on a high power setting. The same was for the nichrome wire; it was much cooler on a low power setting than on a higher power setting.5.

Data:

Nichrome Wire - Test 1 Power InputVoltage (V)Current (mA)Resistance (? ) A0. 000. 000. 00 B1. 000. 1010.

00 C2. 250. 1317. 31 D2. 500.

1714. 71 E3. 000. 2015.

00 F4. 500. 2518. 00 G5.

450. 3018. 17

Nichrome Wire - Test 2 Power InputVoltage (V)Current (mA)Resistance (? ) A0. 000.

000. 00 B0. 750. 107. 50 C2.

000. 1315. 38 D2. 750.

1716. 18 E3. 750. 2018. 75 F4. 900.

2519. 60 G5. 900. 3019. 67

Nichrome Wire - Test 3 Power InputVoltage (V)Current (mA)Resistance (? A0. 000. 000. 00 B0.

850. 108. 50 C1. 950. 1315.

00 D2. 700. 1715. 88 E3. 400. 2017.

00 F4. 650. 2518. 60 G5.

750. 3019. 17

Nichrome Wire - Test 4 Power InputVoltage (V)Current (mA)Resistance (? ) A0. 000. 000.

00 B0. 800. 108. 00 C2.

250. 1317. 31 D2. 650. 1715.

59 E3. 500. 2017. 50 F4. 780.

2519. 12 G5. 930. 3019. 77

Light Bulb - Test 1 Power InputVoltage (V)Current (mA)Resistance (? ) A0.

000. 000. 00 B1. 000. 1010. 00 C2.

000. 1513. 33 D3. 500. 2017. 50 E5.

000. 2520. 00 F6. 500.

2724. 07 G8. 000. 3324. 24

Light Bulb - Test 2Power InputVoltage (V)Current (mA)Resistance (? ) A0. 000. 000. 00 B1.

000. 1010. 00 C2. 250.

1515. 00 D3. 500. 2017. 50

E5.

100. 2520. 40 F6. 550. 2724.

26 G7. 350. 3322. 27

Light Bulb - Test 3 Power InputVoltage (V)Current (mA)Resistance (? ) A0. 000.

000. 00 B1. 000. 1010. 00 C2.

150. 1514. 33 D3. 500. 2017. 50 E5.

100. 2520. 40 F6. 750. 2725. 00 G7.

350. 3322. 27

Light Bulb - Test 4 Power InputVoltage (V)Current (mA)Resistance (? ) A0. 000. 000. 00 B1.

120. 1011. 20 C2. 350.

1515. 67 D3. 570. 2017. 85 E4. 850.

2519. 40 F6. 850. 2725. 37 G7.

350. 3322. 276.

Discussion

In conducting this experiment we also need to take into account of errors in the experiment. One of the main errors is the parallax error.

Parallax error is also known as the ‘viewfinders error’. The error was a problem because it meant that reading the position of the needle against a scale in the voltmeter or ammeter and not clearly seeing the positioning for fine measurements. The resistance of a conductor increases as its temperature increases. With the light bulb, as the power input became higher the heat in the light bulb also rose thus creating greater resistance.This shows that resistance is affected by temperature. Light bulbs have a filament called tungsten.

Tungsten is such a good conductor that its resistance depends on its temperature. The tungsten’s temperature increases the power dissipated by the also bulb increases. In general, power dissipated by the bulb relates to the brightness of the bulb; the higher the power, the brighter the light bulb. The nichrome wire is the other resistor used in this experiment. Nichrome is also a very good resistor. When the power input went up the nichrome started to heat up.

It was required for the nichrome to cool down after extended

periods of time to get more accurate results. Like the light bulb the resistance of the nichrome wire increases as the temperature increases. A way to overcome the parallax error was to find a voltmeter or an ammeter with a scale printed above a narrow strip of mirror. Position your eye so that the needle conceals itself from its own reflection. This assures that the user's line of sight is to the scale and therefore is perpendicular to the mirror.

Another error that could have occurred is using the alligator clips as a switch.Turning the circuit on and off with the switch could have produced variable results. It is recommended that when turning on the circuit hold the switch in place until the readings have been recorded. Another problem was the multimeter.

Because the probes weren’t connected properly on the light bulb and nichrome wire, it was hard to get in the right position and so results were variable. This shows that human carefulness was a key factor for producing the results. In the graphs, after four trials with the light bulb the line that is created is non-ohmic.The nichrome wire however has a line that is more ohmic.

Conclusion

In recreating an experiment for Ohm’s Law, it is proved that as temperature increases so does the resistance. The relationship for current and voltage is that if they both increase so does the resistance. Thus applied voltage is directly proportional to the current that flows i. e. Ohm’s Law. The light bulb is a non-ohmic resistor and the nichrome wire is an ohmic resistor.

Bibliography

1. Butler, Mark 2000,
2. Macmillan Physics 1: Preliminary Course, Macmillan Education Australia Pty Ltd, South YarraChapple,
   

Michael 2003,