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# Physics circuits AS help watch

1. I have a standard answer to the question shown in the scan but I don't know how the p.d. across the 360ohm resistor is calculated to be 3.0V and the same situation for the 120ohm resistor having a p.d. of 3.0V. Could someone please try and explain what equation/calculation I need to do? Thanks in advance.
2. We know that the P.D across each junction is the same, so the Total P.D in the 200 and 120 ohm resistor combination will be 8v.

So we know that the voltage across the 200ohm resistor and the voltage across the 120 ohm resistor will add up to equal 8 volts. Same goes for the 600 and 360 ohm pair.

So We can imagine the 200 and 120 ohm pair like a series circuit. Divide the P.D (8volts) by the total resistance in the junction (200 + 120)

and multiply this answer by the resistance of the resistor you want to calculate the P.D across.

So Let's say I want to find out the voltage across the 120ohm resistor,
I do " 8/ (200+120) which gives me 0.025
and then... " 0.025 x 120" which gives me 3 volts.

Same goes for the other pair. " 8 / (600 + 360)" which gives me 0.00833...
and multiply that by 360 which gives me a final answer of 3 volts.

Hope you understand
3. (Original post by TheTechnoGuy)
We know that the P.D across each junction is the same, so the Total P.D in the 200 and 120 ohm resistor combination will be 8v.

So we know that the voltage across the 200ohm resistor and the voltage across the 120 ohm resistor will add up to equal 8 volts. Same goes for the 600 and 360 ohm pair.

So We can imagine the 200 and 120 ohm pair like a series circuit. Divide the P.D (8volts) by the total resistance in the junction (200 + 120)

and multiply this answer by the resistance of the resistor you want to calculate the P.D across.

So Let's say I want to find out the voltage across the 120ohm resistor,
I do " 8/ (200+120) which gives me 0.025
and then... " 0.025 x 120" which gives me 3 volts.

Same goes for the other pair. " 8 / (600 + 360)" which gives me 0.00833...
and multiply that by 360 which gives me a final answer of 3 volts.

Hope you understand
Thank you so much! That has really helped me understand now!

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