Rtotal = 100 1/Rtotal = 1/R1 + 1/R2 1/100 = 1/R1 + 1/200 Ω R1 = ? 1/R1 = 1/100 - 1/200 R2 = 200 1/R1 = 2/200 - 1/200 Ω 1/R1 = 1/200 R1 = 200 Ω Measuring Current, Voltage and Resistance Like all components, meters (which are used to measure values) have component symbols. Component Name Circuit Symbol Function Measures potential difference. Must be placed in parallel to measure the Voltmeter difference in electrical potential between two points. Measures current. Must be placed in series Ammeter to measure the current flowing in a circuit. Measures resistance. Must be placed in Ohmmeter parallel with the component(s) which are to be measured. They can be used in simple, or more complex circuits in order to investigate the size of any of these quantities. This circuit a battery and a resistor. The diagram also shows how the voltmeter and ammeter must be connected. The voltmeter must be connected in parallel because it is measuring the difference in electrical potential between two points. The ammeter must be connected in series because it is measuring the flow of current THROUGH a component or circuit. The two main are: To find the potential difference across a component, or components, the voltmeter must be placed in parallel with that component or those components. To find the current through a component or components, the ammeter must be placed in series with that component or those components.
Rtotal = 100 Ω R1 = ? R2 = 200 Ω 1/Rtotal 1/100 1/R1 1/R1 1/R1 R1 = 1/R1 + 1/R2 = 1/R1 + 1/200 = 1/100 - 1/200 = 2/200 - 1/200 = 1/200 = 200 Ω Measuring Current, Voltage and Resistance Like all components, meters (which are used to measure values) have component symbols. Component Name Circuit Symbol Function Voltmeter Measures potential difference. Must be placed in parallel to measure the difference in electrical potential between two points. Ammeter Measures current. Must be placed in series to measure the current flowing in a circuit. Ohmmeter Measures resistance. Must be placed in parallel with the component(s) which are to be measured. They can be used in simple, or more complex circuits in order to investigate the size of any of these quantities. This circuit a battery and a resistor. The diagram also shows how the voltmeter and ammeter must be connected. The voltmeter must be connected in parallel because it is measuring the difference in electrical potential between two points. The ammeter must be connected in series because it is measuring the flow of current THROUGH a component or circuit. The two main are: To find the potential difference across a component, or components, the voltmeter must be placed in parallel with that component or those components. To find the current through a component or components, the ammeter must be placed in series with that component or those components.
EE1-ElectricityLOCKERBIE.docx