What happens to the electrical resistance when two resistors are connected in series?

When two resistors are connected in series, the total electrical resistance increases. This is due to the fact that in a series configuration, the current flowing through each resistor must pass through all of them one after the other. The resistance of each individual resistor adds to the total resistance of the circuit.

The total resistance ( R_{total} ) in a series circuit is calculated using the formula:

[ R_{total} = R_1 + R_2 + \ldots + R_n ]

where ( R_1, R_2, \ldots, R_n ) are the resistances of the individual resistors. Since you are summing the values of each resistor, the overall effect is an increase in resistance.

This behavior contrasts with resistors in parallel, where the overall resistance decreases due to multiple paths for current. In series, every additional resistor contributes to more opposition to current flow, hence leading to an increase in total resistance.