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# Circuits Isaac physics help please watch

1. Hey I'm attempting these two questions and can't get the right answers, I was just wondering if someone might be able to help please

https://isaacphysics.org/questions/c...e-7fc1584da06d

https://isaacphysics.org/questions/a...e-7fc1584da06d
2. I'm trying those same two questions and stuck! Is it week 8 of the summer y12 mentoring by any chance? Here's what I've (unsuccessfully ) tried so far the second one is a bridge circuit I'm fairly sure . I'll let you know if I get a solution to either
(Original post by Frankieksd)
Hey I'm attempting these two questions and can't get the right answers, I was just wondering if someone might be able to help please

https://isaacphysics.org/questions/c...e-7fc1584da06d

https://isaacphysics.org/questions/a...e-7fc1584da06d
3. I just worked out the answer to the power problem. Firstly I treated the the parallel circuits as they're components and got 1Ω, 3Ω, 6Ω. Then to get the power I used I = 1. So the voltage is 1V, 3V, 6V.
Current in the small parallel circuit is just .5I.
For line one of the large parallel circuit I worked out the equivalent resistance of the two 20Ω = Req. Then to work out the current through the resistors. Since the the resistance is 1/(20 + Req) and we know that the voltage in parallel is the same the current through through each component is 6/(20+Req). The current of the the parallel 20 can be worked out by using the junction rule

Use V/(R1+R2...) For the second and third line. 6/15 = .4 A and 6/20= .3.
Use P = I2R to find the resistor that has the highest power rating.
When you find the resistor.
Get I by using I=(P/R)1/2 and substitute into V0 = (1+2+6)I
4. And the other question answer is 0.381. Using potential divider equation helps.

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