# Thread: [HELP WANTED] Physics: Electricity

1. ## [HELP WANTED] Physics: Electricity

A 120-V circuit contains a 20.0-Ω resistor and a 40.0-Ω resistor connected in parallel.
a) What is the current through the 40.0-Ω resistor?
b) What is the total current in the circuit?

Any help at all is appreciated!   Reply With Quote

2. Just wondering, what level of physics is this?
I think you can use Ohm's Law.
I=V((1/R1)+(1/R2)) where I is current, V is voltage, and R is resistance.
I haven't done much on electricity so I'm not too sure.  Reply With Quote

3. Based on what you provided, you can conclude that the total current is 9 Ohms.

120(1/20+1/40)
120(3/40)
9  Reply With Quote

4. Ohm is the SI unit for Resistance and not Current which is A for amperes

The formula in Ohm's law I = V/R is applied to each resistor in a parallel circuit to get the current following at that section.
The total current in a parallel circuit is the total current from each section of the parallel circuit.

Therefore,
a)What is the current through the 40.0-Ω resistor?
120V/40Ω= 3A

b)What is the total current in the circuit?
Current at 20Ω resistor - 120V/20Ω= 6A
Total current in the circuit - 6A+3A= 9A  Reply With Quote

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