Question

Why is the answer B? Must we use percentage uncertainty? When must uncertainty be one significant figure?

Answer 1

Answer:

B. 380 ± 10 Ω

Explanation:

The resistance can be calculated using the following equation

R = V/I

Where V = 2.00 ± 0.02 V and I = 5.3 ± 0.1 mA

First, we need to convert 5.3 ± 0.1 mA to A, so

5.3 ± 0.1 mA x 1 A/1000 mA = 0.0053 ± 0.0001 A

Then, we can calculate the resistance as

R = 2.0/0.0053 = 377.35 Ω

Now, we can calculate the uncertainity using the following equation:

$(\frac{\Delta V}{V}+\frac{\Delta I}{I})R=(\frac{0.02}{2.00}+\frac{0.1}{5.3})377.35=10.96\text{ }\Omega$

Therefore, the approximate answer is

B. 380 ± 10 Ω