The total current delivered to a number of devices connected in parallel is the

Question

The total current delivered to a number of devices connected in parallel is the sum of the individual currents in each device. Circuit breakers and resettable automatic switches that protect against a dangerously large total current by "opening" to stop the current at a specified safe value. A 1570-W toaster, a 1180-W iron, and a 1210-W microwave oven are turned on in a kitchen. As the drawing shows, they are all connected through a 20-A circuit breaker to an ac voltage of 120 V. (a) What is the equivalent resistance of the three devices? (b) What is the total current delivered by the source? (Will the breaker "open" in this case?)

http://i44.tinypic.com/2z72bfk.gif

Explanation / Answer

total power = 1570+1210+1180 = 3960 watts A) P = V^2/R R = v^2/P=120^2 /3960= 3.6ohms B) I = V/R = 120/3.6 =33.33 A the breaker gets open because the consumed current is more than the rated current of circuit breaker

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.