What is the formula for Er1 in a DC circuit?

In a DC circuit, the formula for calculating the voltage across a resistor, known as Er1, is derived from Ohm's Law, which states that voltage (V) is equal to the current (I) multiplied by the resistance (R). This fundamental relationship is expressed mathematically as V = I * R.

In this case, It represents the total current flowing through the circuit, and R1 represents the resistance of the specific resistor for which you are calculating the voltage drop. Therefore, when you multiply the total current (It) by the resistance (R1), you determine the voltage drop across that resistor. This is crucial for analyzing how much voltage is being used by each component in the circuit.

By applying this understanding of Ohm's Law, you confirm that the correct formula for Er1 in a DC circuit is indeed It * R1.