Question

in a circuit two resistors of 100 ohm and 80 ohm are connected in parallel. The parallel group is then connected in series with a 100 ohm resistor what is the total resistance of the circuit

Answer 1

When resistors are connected in parallel, the total resistance is given by the formula:

1/𝑅𝑡𝑜𝑡𝑎𝑙 = 1/𝑅1 + 1/𝑅2

Where 𝑅1 and 𝑅2 are the resistances of the two resistors.

Let's calculate the total resistance of the parallel group:

1/𝑅𝑡𝑜𝑡𝑎𝑙 = 1/100 + 1/80
1/𝑅𝑡𝑜𝑡𝑎𝑙 = 0.01 + 0.0125
1/𝑅𝑡𝑜𝑡𝑎𝑙 = 0.0225

Now, let's calculate the total resistance of the circuit when the parallel group is connected in series with a 100 ohm resistor:

𝑅𝑡𝑜𝑡𝑎𝑙 = 100 + 100
𝑅𝑡𝑜𝑡𝑎𝑙 = 200 ohms

Therefore, the total resistance of the circuit is 200 ohms.