Potential difference
https://theonlinephysicstutor.com/downloads/AQA%20Potential%20dividers.pdf
Hi, please does anyone know how to solve Number 3iii.
Hi, please does anyone know how to solve Number 3iii.
Original post by Joinedup
You can combine the 2.2k and 8.0k using the rule for resistances in parallel...
1/Requiv = 1/R1 + 1/R2....
1/Requiv = 1/R1 + 1/R2....
yhh, I've done that but I keep getting a different answer for the pd across the potentiometer. The mark scheme answer is 4.4V
OK after combining resistors you're left with 1.725k that represents the 8k in parallel with the 2.2k - this is the resistor you're now interested in finding the PD across.
the right hand side of the potentiometer hasn't gone away so you can solve by finding the current through 1.725k in series with 1.8k and then the PD across a 1.725k resistor carrying that current
or you could use the potential divider equation (which is equivalent)
Va = Vin (Ra/Ra+Rb)
Ra is the resistor you're interested in and Va is the PD across that resistor
the right hand side of the potentiometer hasn't gone away so you can solve by finding the current through 1.725k in series with 1.8k and then the PD across a 1.725k resistor carrying that current
or you could use the potential divider equation (which is equivalent)
Va = Vin (Ra/Ra+Rb)
Ra is the resistor you're interested in and Va is the PD across that resistor
Original post by Joinedup
OK after combining resistors you're left with 1.725k that represents the 8k in parallel with the 2.2k - this is the resistor you're now interested in finding the PD across.
the right hand side of the potentiometer hasn't gone away so you can solve by finding the current through 1.725k in series with 1.8k and then the PD across a 1.725k resistor carrying that current
or you could use the potential divider equation (which is equivalent)
Va = Vin (Ra/Ra+Rb)
Ra is the resistor you're interested in and Va is the PD across that resistor
the right hand side of the potentiometer hasn't gone away so you can solve by finding the current through 1.725k in series with 1.8k and then the PD across a 1.725k resistor carrying that current
or you could use the potential divider equation (which is equivalent)
Va = Vin (Ra/Ra+Rb)
Ra is the resistor you're interested in and Va is the PD across that resistor
Yhh , I got it, thank youuu
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