week-12-1

week-12-1 - In the circuit shown, R3 is greater than R2,...

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In the circuit shown, R 3 is greater than R 2 , and R 2 is greater than R 1 . is the electromotive force of the battery whose internal resistance is negligible. Which of the three resistors has the greatest current flowing through it? a) R 1 b) R 2 c) R 3 d) R 1 and R 2 are equal, and greater than R 3 e) They are all equal
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The plot of electric current as a function of time for an alternating current is a sinusoidal curve . The average value of an ordinary alternating current is zero. The power dissipated in a resistance is proportional to the square of the current. The effective current or rms current is obtained by squaring the current, averaging this value over time, and taking the square root of the result. The effective current I eff is 0.707 times the peak current I peak .
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A 60-W light bulb is designed to operate on 120 V ac. What is the effective current drawn by the bulb? a) 0.2 A b) 0. 5 A c) 2.0 A d) 72 A e) 7200 A P 60 W V effective 120 V P I V I P V 60 W 120 V 0.5 A
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Household circuits are wired in parallel so that different appliances can be added to or removed from the circuit without affecting the voltage available. As you add more appliances, the total current drawn increases, because the total effective resistance of the circuit decreases when resistances are added in parallel. Since too large a current could cause the wires to overheat, a fuse or circuit breaker in series with one leg of the circuit will disrupt the circuit if the current gets too large. Appliances with larger power requirements (stoves, clothes dryers, etc) are usually connected to a separate 220-V line.
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A voltmeter measures the voltage difference between two points in a circuit, or across an element in a circuit It is inserted in parallel with the element whose voltage difference is being measured. A voltmeter should have a large resistance, so that it does
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week-12-1 - In the circuit shown, R3 is greater than R2,...

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