Resistors in series and in parallel

In summary, the conversation discusses finding the voltage, resistance, and current in a circuit with a 20V battery and multiple resistors. The total resistance is calculated by adding the individual resistances, and the total current is found to be 1.54A. The voltage and current for each individual resistor are then calculated using the total resistance and current. The question of whether the total current should equal 1.54A is raised. The explanation for the voltages in red is also provided.
  • #1
Moninder
22
0
v0ynsWi.jpg


!20V battery.I need to Find Voltage, Resistance and Current in all resistors and total.
This is what I did so far.
Added 13ohms +15 ohms, then took all 3 of those and made it into one, whihc gave me 7.2258ohms.
Did the same for the 72 and 45 to get 27.7 ohms.
Then found the total resistance as 77.92 ohms. Found I total , current to be 1.54A
And for the 19ohm resistors I got V=29.26V I=1.54A
For 24ohm, V=36.96 I=1.54A
And I think for the 32 ohm V=29.26 I=0.91A
For 72ohm and 45 ohm V=27.7ohm and if that is it, should total current equal 1.54 instead of 0.88A?
 
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  • #2
Moninder said:
v0ynsWi.jpg


!20V battery.I need to Find Voltage, Resistance and Current in all resistors and total.
This is what I did so far.
Added 13ohms +15 ohms, then took all 3 of those and made it into one, whihc gave me 7.2258ohms.
Did the same for the 72 and 45 to get 27.7 ohms.
Then found the total resistance as 77.92 ohms. Found I total , current to be 1.54A
And for the 19ohm resistors I got V=29.26V I=1.54A
For 24ohm, V=36.96 I=1.54A
And I think for the 32 ohm V=29.26 I=0.91A
For 72ohm and 45 ohm V=27.7ohm and if that is it, should total current equal 1.54 instead of 0.88A?

How did you get the voltages in red?

The voltage is the same across all parallel connected resistors. It is equal to their resultant multiplied by the total current. The voltage across the 32 Ω resistor is the same as the voltage across the parallel resultant: 7.226*1.54. Dividing this voltage by the individual parallel resistances, you get the currents.

ehild
 

1. What is the purpose of using resistors in series and in parallel?

The purpose of using resistors in series and in parallel is to change the overall resistance in a circuit. In series, resistors add together to create a higher overall resistance, while in parallel, resistors combine to create a lower overall resistance.

2. What is the difference between resistors in series and in parallel?

In series, resistors are connected end-to-end, creating one path for current to flow through. In parallel, resistors are connected side-by-side, creating multiple paths for current to flow through.

3. How do you calculate the total resistance in a series circuit?

To calculate the total resistance in a series circuit, you simply add together the individual resistances of each resistor. This can be represented by the formula: R(total) = R1 + R2 + R3 + ... + R(n).

4. How do you calculate the total resistance in a parallel circuit?

To calculate the total resistance in a parallel circuit, you must first find the reciprocal of each individual resistance. Then, add together all of the reciprocals and take the reciprocal of the sum. This can be represented by the formula: R(total) = 1 / (1/R1 + 1/R2 + 1/R3 + ... + 1/R(n)).

5. What happens to the current and voltage in a series and parallel circuit?

In a series circuit, the current remains constant throughout all resistors, while the voltage drops across each resistor. In a parallel circuit, the voltage remains constant across all resistors, while the current splits and flows through each resistor individually.

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