What resistance values can be obtained by connecting three resistors in all possible ways
What resistance values can be obtained by connecting three resistors in all possible ways, if the resistance of each is 6 ohms? What resistance values can be obtained by connecting three resistors in all possible ways, if the resistance of each is 6 ohms?
Given:
R = 6 Ohm – resistance of each resistor;
n = 3 is the number of resistors.
It is required to determine what resistance values can be obtained by connecting three identical resistors in all possible ways.
1) Connect all resistors in series:
R1 = R + R + R = R * n = 3 * 6 = 18 ohms.
2) Connect all resistors in parallel:
1 / R1 = 1 / R + 1 / R + 1 / R;
1 / R1 = n / R;
R1 = R / n = 6/3 = 2 ohms.
3) First we connect two resistors in series, and then the third resistor – in parallel:
R1 = R + R = 2 * R = 2 * 6 = 12 ohms.
1 / R2 = 1 / R1 + 1 / R;
1 / R2 = (R1 + R) / (R1 * R);
R2 = R1 * R / (R1 + R) = 12 * 6 / (12 + 6) = 72/18 = 4 ohms.
4) We connect first two resistors in parallel, and then the third resistor – in series:
1 / R1 = 1 / R + 1 / R;
1 / R1 = 2 / R;
R1 = R / 2 = 6/2 = 3 ohms.
R2 = R1 + R = 3 + 6 = 9 ohms.
Answer: when connecting resistors in all possible ways, you can get resistance values equal to 18 Ohms (first method), 2 Ohms (second method), 4 Ohms (third method) and 9 Ohms (fourth method).