Resistors with resistance R1 = 300 Ohm and R2 = 600 Ohm are connected in parallel.

| September 14, 2021 | education

Resistors with resistance R1 = 300 Ohm and R2 = 600 Ohm are connected in parallel. Find the current in the first resistor if the current in the second resistor is 0.4 A.

R1 = 300 ohms.

R2 = 600 ohms.

I2 = 0.4 A.

I1 -?

For parallel connection of conductors, the following ratios are valid:

I = I1 + I2, U = U1 = U2, R = R 1 * R2 / (R 1 + R2).

Where I1, I2 are the current in the first and second resistor, U1, U2 are the voltage across the first and second resistor, R 1, R2 m are the resistance of the first and second resistor, I, U, R are the current strength, voltage, resistance of the entire section chains

According to Ohm’s law for a section of the circuit, we express the voltage across the second resistor U2.

I2 = U2 / R2.

U2 = I2 * R2.

Let’s write Ohm’s law for the first resistor: I1 = U1 / R1. Since U = U1 = U2, then

I1 = U2 / R1 = I2 * R2 / R1.

I1 = 0.4 A * 600 Ohm / 300 Ohm = 0.8 A.

Answer: the current in the first resistor is I1 = 0.8 A.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.