# Calculate Voltage & Power in Series Circuit w/ 3 Resistors

• himura137
In summary, three resistors are connected in series across a battery with values of 4.7 ohms and 17.7 W, 23.1 ohms and 13.9 W, and 12.8 ohms and 12.9 W. To find the greatest voltage that the battery can have without one of the resistors burning up, the maximum current was calculated using the power equation. The lowest current was used to determine the total voltage of the battery. It was correctly approached by calculating the series current, which is the same for each resistor. This allows for the determination of the maximum total voltage of the battery.
himura137
Three resistors are connected in series across a battery. The value of each resistance and its maximum power rating are as follows: 4.7 ohms and 17.7 W, 23.1ohms and 13.9 W, and 12.8ohms and 12.9 W. (a) What is the greatest voltage that the battery can have without one of the resistors burning up? (b) How much power does the battery deliver to the circuit in (a)?

A - to find the greatest voltage, i needed the max current so i used P= IR^2 for each one to and find the current, the lowest current will provide the max current for the circuit without the resistor burning up. Then use the current multiple by the sum of resister to find the voltage.

My question is , I though when resistors are placed in series (if voltage is given), the current is the same through out, how come in this problem, i had to find current separately. as oppose to finding the sub of the resistance and multiplying it by the voltage (if given)

Last edited:
I believe that from P=VI and V=IR,
you get P=(IR)I
and finally P=I^2 * R

himura137 said:
My question is , I though when resistors are placed in series (if voltage is given), the current is the same through out, how come in this problem, i had to find current separately. as oppose to finding the sub of the resistance and multiplying it by the voltage (if given)
You approached it correctly. The series current is indeed the same in each resistor, so you can calculate the max current allowed based on the smallest power-handling resistor. That defines the current for the series resistors, which gives you the max total voltage of the battery.

## What is a series circuit?

A series circuit is a circuit in which the components are connected end to end, forming a single loop. This means that the current flows through each component in sequence.

## How do you calculate voltage in a series circuit with 3 resistors?

To calculate voltage in a series circuit with 3 resistors, you need to add up the individual voltages of each resistor. This is known as Kirchhoff's Voltage Law. The total voltage is equal to the sum of the individual voltages.

## How do you calculate power in a series circuit with 3 resistors?

To calculate power in a series circuit with 3 resistors, you can use the formula P = VI, where P is power, V is voltage, and I is current. You can calculate the current by dividing the total voltage by the total resistance, which is equal to the sum of the individual resistances.

## What is the difference between voltage and power?

Voltage is the potential difference between two points in a circuit, while power is the rate at which energy is being transferred or used. In simpler terms, voltage is the force that pushes the current through a circuit, while power is the amount of work being done by the current.

## Are there any shortcuts for calculating voltage and power in a series circuit with 3 resistors?

Yes, you can use Ohm's Law, which states that voltage is equal to current multiplied by resistance (V = IR). This can help you calculate voltage and power more quickly and efficiently in a series circuit with 3 resistors.

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