WAEC Physics 2021 Theory — Question 23
Question 23 of 35 from the West African Examinations Council (WAEC) Physics 2021 Theory paper, with the correct answer and a full explanation.
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11(a). (i) What is meant by the root-mean-square value of an alternating current? (ii) Define impedance of an alternating current circuit.
Model answer
(i) The r.m.s. value of an alternating current is the value of a steady direct current that produces the same heating effect in a given resistor as the alternating current. (ii) Impedance is the total opposition offered by a circuit to the flow of alternating current, combining both resistive and reactive components.
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