A direct current of 5A is superimposed on an alternating current I = 10 sin ωt flowing through the wire. The effective value of the resulting current will be
Correct answer: B. 5/√3 A
- A. 15/√2 A
- B. 5/√3 A
- C. 5/√5 A
- D. 15 A
Explanation
To find the effective current when DC and AC are combined:DC current = 5 AAC current = 10sin(ωt)10/sin(omega t) → RMS = 10/√2 =5√2 AEffective current:Ieff=52+(52)2=25+50=75=53 AI_{eff} = √[5²+ (5/√2)²] = √{25 + 50} =√{75} = 5/√{3} A✅ Correct answer: 5/√3 A.
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About Alternating Current
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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