Download Aim: To determine whether the object allocated to you is an Ohmic

Year 12 Physics
Ohms Law (E3)
Aim:
To determine whether the object allocated to you is an Ohmic or non-Ohmic
conductor.
Equipment:
power pack, ammeter, voltmeter, unknown resistor
Q1. What is Ohms Law? Explain it in words using correct physics terms. Define the
terms Ohmic resistors and non-Ohmic resistors in terms of Ohms Law.
Method/Results:
1. Set up the following circuit using the object assigned to
you in the place of the resistor.
2. Copy a table similar to this one leaving room to add
more voltage values.
Current (A)
Voltage (V)
0.0
A
V
Resistor coil in
water.
Work quickly to
prevent burning
ruler
3. Starting with the power supply at 0V measure and record the current and voltage for
your resistance object. As the value on the power supply is only an estimate you
need to be recording the value of the voltmeter in your chart.
4. Increase the voltage to 0.5V and record the current. Use your voltmeter to tell you
when you have altered your power supply sufficiently to give you 0.5V across the
resistor.
5. Complete the table for 0.0V to 12V in 0.5V steps you will need to work quickly as
the non-ohmic resistors can not be powered for to long without burning.
6. Draw a graph of Voltage vs Current.
Q2. Does your graph show a relationship between the current and voltage? Explain
your answer and describe this relationship in words and equation.
Q3. What sort of graph does an Ohmic resistor produce? Sketch this.
Q4. What sort of graph does a non-Ohmic resistor produce? Sketch this.
Q5. You should be able to decide whether you have an Ohmic or non-Ohmic
conductor by comparing the graphs. Which have you? Got explain your
reasoning.
Q6. If an Ohmic conductor carries a current of 10mA when a voltage of 6V is placed
across it. What will be the voltage for a current of (a)5mA, (b)20mA?
Conclusion:
Write a conclusion that summaries what you have found in the process of doing this
experiment. Support your conclusion with relevant theory and reasoning.
Year 12 Physics
Ohms Law (E3)
Aim:
To determine whether the object allocated to you is an Ohmic or non-Ohmic
conductor.
Equipment:
power pack, ammeter, voltmeter, unknown resistor
Q1. What is Ohms Law? Explain it in words using correct physics terms. Define the
terms Ohmic resistors and non-Ohmic resistors in terms of Ohms Law. √√
Method/Results:
1. Set up the following circuit using the object assigned to
you in the place of the resistor.
2. Copy a table similar to this one leaving room to add
more voltage values.
√
Current (A)
Voltage (V)
0.0
A
V
Resistor coil in
water.
Work quickly to
prevent burning
ruler
3. Starting with the power supply at 0V measure and record the current and voltage for
your resistance object. As the value on the power supply is only an estimate you
need to be recording the value of the voltmeter in your chart.
4. Increase the voltage to 0.5V and record the current. Use your voltmeter to tell you
when you have altered your power supply sufficiently to give you 0.5V across the
resistor.
5. Complete the table for 0.0V to 12V in 0.5V steps you will need to work quickly as
the non-ohmic resistors can not be powered for to long without burning.
6. Draw a graph of Voltage vs Current. √title & data √x axis √y axis √best fit
Q2. Does your graph show a relationship between the current and voltage? Explain
your answer and describe this relationship in words and equation. √√
Q3. What sort of graph does an Ohmic resistor produce? Sketch this. √
Q4. What sort of graph does a non-Ohmic resistor produce? Sketch this. √
Q5. You should be able to decide whether you have an Ohmic or non-Ohmic √
conductor by comparing the graphs. Which have you? Got explain your
reasoning.
Q6. If an Ohmic conductor carries a current of 10mA when a voltage of 6V is placed
across it. What will be the voltage for a current of (a)5mA, (b)20mA? √√
Conclusion:
Write a conclusion that summaries what you have found in the process of doing this
experiment. Support your conclusion with relevant theory and reasoning. √
Year 12 Physics
Ohms Law (E3)
Total÷1.5= /10