Two 5-ohm resistors in parallel have an equivalent resistance of?

Two 5-ohm resistors in parallel have an equivalent resistance of?

• A. 5 Ohms
• B. 2.5 Ohms
• C. 10 Ohms
• D. 1 Ohm

Answer: (B)

In parallel, resistances combine by adding their reciprocals. So 1/R_eq = 1/R1 + 1/R2. With two 5-ohm resistors: 1/R_eq = 1/5 + 1/5 = 2/5, which gives R_eq = 5/2 = 2.5 ohms. This outcome fits the idea that parallel connections provide multiple paths for current, reducing the overall resistance below any one resistor. The other numbers would come from treating them as a series connection (which would yield 10 ohms) or from a misapplication of the parallel rule, but the correct equivalent resistance is 2.5 ohms.

In parallel, resistances combine by adding their reciprocals. So 1/R_eq = 1/R1 + 1/R2. With two 5-ohm resistors: 1/R_eq = 1/5 + 1/5 = 2/5, which gives R_eq = 5/2 = 2.5 ohms. This outcome fits the idea that parallel connections provide multiple paths for current, reducing the overall resistance below any one resistor. The other numbers would come from treating them as a series connection (which would yield 10 ohms) or from a misapplication of the parallel rule, but the correct equivalent resistance is 2.5 ohms.