Plusivo DM501D - Page 40

Second, we connect a resistor with the battery and measure its voltage, in our case we will
connect a 510 Ω resistor.
The measured voltage in this figure is 8.55 V DC.
Third, we will do some calculations using Ohm’s law.
● Calculate the current passing through the resistor:
𝑅
𝑉
𝑅
= 𝐼
8.55 𝑉
510 Ω
= 0. 0168 𝐴 = 16. 8 𝑚𝐴
● Subtract the voltage of the battery from the voltage of the resistor:
𝐵
𝑉
− 𝑅
𝑉
= 𝐵
𝑅𝑉
8. 95 𝑉 − 8. 55 𝑉 = 0. 40 𝑉
● Now, we have the current and the voltage on the internal resistance, so we can calculate the
value of the internal resistor:
𝑉
𝐼
= 𝐼
𝐵𝑅
0.40 𝑉
0.0168 𝐴
= 23. 81 Ω
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Mastering the Art of Measurement (DM501D Digital Multimeter) r.01 www.plusivo.com