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Ch 26: Direct-Current Circuits
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoYoung & Freedman Calc 14th EditionCh 26: Direct-Current CircuitsProblema 52b
Capitolo 26, Problema 52b

The heating element of an electric dryer is rated at 4.1 kW when connected to a 240 V line. What is the resistance of the dryer's heating element at its operating temperature?

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First, understand the relationship between power, voltage, and resistance. The formula to use here is the power formula: \( P = \frac{V^2}{R} \), where \( P \) is the power, \( V \) is the voltage, and \( R \) is the resistance.
Rearrange the formula to solve for resistance \( R \). This gives us \( R = \frac{V^2}{P} \).
Substitute the given values into the formula. The power \( P \) is 4.1 kW, which is equivalent to 4100 W, and the voltage \( V \) is 240 V.
Calculate \( V^2 \) by squaring the voltage: \( V^2 = 240^2 \).
Finally, divide \( V^2 \) by \( P \) to find the resistance \( R \): \( R = \frac{240^2}{4100} \). This will give you the resistance of the dryer's heating element at its operating temperature.

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Electric Power

Electric power is the rate at which electrical energy is transferred by an electric circuit. It is measured in watts (W) and calculated using the formula P = VI, where P is power, V is voltage, and I is current. Understanding power is crucial for determining how much energy the dryer uses.
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Power

Ohm's Law

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance. It is expressed as V = IR, where V is voltage, I is current, and R is resistance. This law is essential for calculating the resistance of the dryer's heating element.
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Resistance and Ohm's Law

Resistance

Resistance is a measure of the opposition to the flow of electric current in a circuit. It is measured in ohms (Ω) and affects how much current flows for a given voltage. Calculating the resistance of the dryer's heating element involves using the power and voltage values to find how much the element resists the current flow.
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Resistivity & Resistors in Circuits
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