NCTI Installer Technician Practice Test

In a DC series circuit, the total resistance (RT) is the sum of all the individual resistances in the circuit. Therefore, to find the value of R2, you can rearrange the formula for total resistance:

RT = R1 + R2 + R3 + R4.

Given the values:

- R1 = 33 ohms

- R3 = 47 ohms

- R4 = 56 ohms

- RT = 197 ohms

You can substitute the known values into the equation:

197 ohms = 33 ohms + R2 + 47 ohms + 56 ohms.

Now, combine the resistances R1, R3, and R4:

33 + 47 + 56 = 136 ohms.

Next, substitute this sum back into the equation:

197 ohms = 136 ohms + R2.

To isolate R2, subtract 136 ohms from both sides:

R2 = 197 ohms - 136 ohms

R2 = 61 ohms.

Thus, the value of R2 is 61 ohms, which aligns with the correct answer. The total resistance calculation confirms the value derived is indeed accurate based on the