you ca obtain four 20 ohms resistors from te stock room.
ow can you aciee a resistance of 50 ohms uder these circumstances
2 series with 2 in parellel
Correct. R = 20 + 20 + 1/[1/20 + 1/20)]
= 50
To achieve a resistance of 50 ohms using four 20 ohm resistors, you can connect them in a specific configuration called a series-parallel combination. Here's how you can do it:
1. First, connect two pairs of resistors in series. This means combining two resistors together in a line, where the current passes through both resistors one after the other. Each pair of resistors will have a combined resistance of 20 + 20 = 40 ohms.
2. Next, connect the two pairs of resistors in parallel. This means connecting the free ends of each pair together. The total combined resistance of two resistors in parallel is calculated as: 1 / (1/R1 + 1/R2). In this case, the combined resistance will be: 1 / (1/40 + 1/40) = 1 / (1/20) = 20 ohms.
By connecting the resistors as described, the series combination (40 + 40 = 80 ohms) followed by the parallel combination (20 ohms) will result in a total resistance of 20 ohms. This meets the requirement of achieving a resistance of 50 ohms using the four 20 ohm resistors.