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Question 4.5: An alternating current has a peak-peak value of 50 mA. What ......

An alternating current has a peak-peak value of 50 mA. What is its r.m.s. value?

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The corresponding multiplying factor (found from Table 4.1) is 0.353. Hence:

I_{r.m.s.} = 0.353 × V_{pk-pk} = 0.353 × 0.05 = 0.0177 A

(or 17.7mA).

Table 4.1 Multiplying factors for average, peak, peak-peak and r.m.s. values
Given quantity Wanted quantity
Average Peak Peak– peak r.m.s.
Average 1 1.57 3.14 1.11
Peak 0.636 1 2 0.707
Peak– peak 0.318 0.5 1 0.353
r.m.s. 0.9 1.414 2.828 1

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