A 5 ohm and a 10 ohm resistor are wired in series. What is the total resistance?

In a series circuit, the total resistance is found by simply adding the resistance values of each resistor together. This is because the current flowing through the circuit passes through each resistor sequentially, experiencing the full resistance of each one.

In this case, you have a 5-ohm resistor and a 10-ohm resistor. By adding these two values, you calculate the total resistance:

5 ohms + 10 ohms = 15 ohms.

Thus, the total resistance is correctly identified as 15 ohms. This understanding of series circuits is fundamental in electrical engineering and is essential for anyone working with resistors in practical applications.