IntoScienceAim: To revise and complete the “Electrical Circuits” module on IntoScience Keywords: Current, voltage This lesson we continued on IntoScience to revise and understand the first STEM question for this week, “What is voltage and current?” and also the second STEM question, "How do we measure voltage and current within and electrical circuit." Below are my answers to these questions and also some images from the lesson. This graph illustrates the relationship between current and voltage. It demonstrates how as the strength of the electricity increases, logically, the strength at which it is flowing increases as well. The graph shows us that as more 1.5V batteries are added, the current increases by 0.15A. This graph illustrates how as more light bulbs are added and the resistance increases respectively, the current decreases. The table on the left shows us that each light bulb adds 10ohms, decreasing the current by from 60A, to 30A, then 20A and 15A. This final diagram, which also appeared in last week’s blog, is a triangle illustrating Ohm’s Law. This states that Voltage (V) = Current (I) x Resistance (R), as voltage is ‘over’ both current and resistance, illustrating that V/I = R and V/R = I, therefore concluding that V = I x R. Stem Question 4: What is voltage and current?
Current and voltage are two interrelated characteristics of electricity. Although they are similar in ways and have large impacts on each other, they are two completely separate things. Voltage is the power or strength of the electrons and is measured in volts. A higher voltage means higher power and a higher risk when handling electricity. Voltage decreases as resistance increases, such as when more components are added to the circuit, as the electricity has to push through each component, losing its strength. Voltage will always decrease in a series circuit as the electrons have to flow through each component consecutively. However, in a parallel circuit which every branch only has one component, the voltage would remain constant. This is because, unlike the series circuit, the voltage doesn’t have to share itself amongst multiple components in the same branch. Current is the strength or ‘push’ of the flow of electrons, rather than the strength of the electricity itself. Current is measured in amperes or amps, and unlike voltage, current remains constant in a series circuit. This is due to a series circuit having only one path to flow down, meaning it is unable to split itself amongst conductors. Due to a parallel circuit having multiple branches for the electrons to flow down, current is shared equally among the branches in a series circuit. Stem Question 5: How do we measure voltage and current in a circuit? Voltage and current can be measured in a circuit using a voltmeter and an ammeter respectively. A voltmeter must be placed in parallel to the component it is measuring. This is because the voltmeter works by measuring the voltage at the input to the component and also the output. From this the voltmeter calculates the voltage and displays it on its dials as volts. (V) Current is measured using an ammeter and it must be placed in series with the component(s) in order to measure the current. Current is the flow of electrons and therefore the ammeter needs to be placed in circuit so that it can measure the current as the flow passes through it. The ammeter then displays this on its dial as amperes or amps. (A) Lesson Summary: Answered the question, “What is voltage and current?” Revised Ohm’s Law Revised the impacts that increases and decreases in voltage, current and resistance have on each other.
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