Question

Three identical resistors have an equivalent resistance of 65 Ω when connected in parallel. Part A What is their equivalent resistance when connected in series? Express your answer to two significant figures and include the appropriate units.

Answer 1

Answer:

590 ohms

Explanation:

Let the resistance of each resistor be 'R'.

Given:

Equivalent resistance of the three resistors in parallel $(R_p)[/tex[ = 60 ohm

We know that, the equivalent resistance of three identical resistors in parallel is given as:

[tex]R_p=\frac{R}{3}$

Plug in the given values and solve for 'R'. This gives,

$65=\frac{R}{3}\\\\R=65\times 3\\\\R=195\ ohm$

Now, the equivalent resistance of the three identical resistors in series is the sum of each of the resistors. Therefore,

$R_s=R+R+R\\\\R_s=3R\\\\R_s=3\times 195=585\ ohm$

As the question asks to round off to two significant figures, so we add 1 to the second significant figure because the number next to 8 is 5 which is greater than or equal to 5. So, the number becomes 590.

Hence, the equivalent resistance in series is 590 ohms.