If a series circuit consists of resistances of 20, 50, and 80 ohms, what would be the current flowing with a supply voltage of 400 V?

To find the current flowing through a series circuit with given resistances and supply voltage, you first need to calculate the total resistance in the circuit. In a series circuit, the total resistance is simply the sum of all individual resistances.

In this case, we have resistances of 20 ohms, 50 ohms, and 80 ohms. The total resistance ( R_{total} ) is calculated as follows:

[

R_{total} = 20 + 50 + 80 = 150 , \text{ohms}

]

Next, using Ohm's law, which states that current (I) is equal to the voltage (V) divided by the resistance (R), can be applied here:

[

I = \frac{V}{R_{total}}

]

Substituting in the values:

[

I = \frac{400 , \text{V}}{150 , \text{ohms}}

]

Calculating this yields:

[

I = \frac{400}{150} \approx 2.67 , \text{A}

]

This calculation confirms that the current flowing in the circuit is approximately 2.