Is a Filament Bulb an Ohmic Resistor?
First of all I did some research because to answer the question 'Is A
Filament Bulb an Ohmic Resistor' I needed to know what an ohmic
resistor was.
OHM'S LAW
The current flowing through a metallic conductor is proportional to
the potential difference. This is only true when the temperature is
constant.
If you read the current as you change the potential difference across
a conductor the ratio V/I (volts over amps) is the same if it is
ohmic.
From digitalbrain.com
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An ohmic resistor is a component in which Ohm's law is satisfied.
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OHMIC
VOLTS
[IMAGE] NON OHMIC
AMPS
Preliminary Experiment: Resistance through a wire
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In this experiment we used a meter stick with wire running down it to
measure the resistance at different distances to decide whether
resistance increases over distance. We changed the voltage or
potential difference 10 times at each length, but in the results table
and graph I have only used the first result from each measurement.
APPARATUS
Meter stick mounted with wire
1 Ammeter
1 Voltmeter
Wire
1 Variable resistor
Crocodile clips
METHOD
1. Attach the ammeter and the voltmeter to the meter stick and
variable resistor.
2. Connect the variable resistor to the power supply and the meter
stick.
3. Plug power supply into the mains and switch on.
4. Check that the voltmeter is showing positive.
Length-cms
Amps-I
Volts-Potential Difference
Resistance-Ohms
0
4.85
0.04
0.008247423
10
2.38
0.46
0.193277311
20
2.08
0.67
0.322115385
30
2.38
1
0.420168067
40
2.2
1.22
0.554545455
50
1.95
1.49
0.764102564
60
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5. Put the stirring wire through the second hole of the stopper. Insert the stopper, thermometer, and wire into the test tube. Make sure that the thermometer bulb is below the surface of the solution.
Volume's Effect on a Copper Sulphate Solution We are trying to find out if the current though a copper sulphate solutions volume is increased. To find this information out I shall perform an experiment using the following equipment; · 1 power pack · 1 beaker · 2 carbon rods for anode and cathode · 1 ammeter · 1 measuring cylinder · 2 crocodile clip wirers I shall also be using 60cm3 volume of copper sulphate in my preliminary results to decide upon the concentration of copper sulphate and the voltage I shall use. The following diagrams show the step by step process in which I will do my experiment; [IMAGE] [IMAGE] [IMAGE] [IMAGE] I will take 10 readings from 10cm3 to 100cm3. I will repeat my experiment to give my experiment a fair average. I will keep the power pack the beaker the carbon rods the crocodile clips the ammeter the concentration of copper sulphate and the measuring cylinder the same each time I do the experiment this experiment.
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equation V = IR. V - volts, I - current and R - resistance. I plotted
When many people think about the element Tungsten, one common visual tends to come to mind; a light bulb. Although most know Tungsten for being used in the light bulb, it has many other uses as well that aren’t as commonly known. Tungsten was first discovered by two brothers in Spain during 1783. The brothers were named Juan Jose and Fausto de Elhuyar, and they discovered Tungsten while working one day. They were the first people whom discovered that Tungsten had the ability to become an element, so they combined reduced tungstic acid with charcoal, and made a new creation. They decided to call this new creation Wolfram. Wolfram was the original name for Tungsten. It is also the reason as to why the symbol for Tungsten on the periodic table is a W. Tungsten does not have countless amounts of natural isotopes, but it still has a fair amount. Tungsten contains about five naturally occurring isotopes, and they are Tungsten-180, Tungsten-182, Tungsten-183, Tungsten-184, and Tungsten-186.
I also decided to use a wooden block to keep hold of the wire, because
F Another wire, or exact same properties (Nickel Chrome, thickness 34). mm and length 30cm) was placed on top of the previous wire, in the same position, both straight and flat. F. The power was turned on again and the same procedure was repeated. recording current and voltage at three points on the variable. resistor.
There fore less current passes through with the same voltage. Simply it is how hard it is for the electrons to pass through the wire. Temperature: When the metal wire is heated , more energy s given to the atoms, therefore they vibrate more. From this there is a greater chance of collisions with the electrons and they are impeded more, therefore less charge is passed by the electrons and the resulting current is reduced. This means while conducting the experiment the temperature of the wire must be kept constant to maintain a safe and fair test.
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
V(voltage) I (current) Therefore, I = V R Therefore, if V is constant, in order to increase I, R must decrease.