27. Resistors & DC Circuits

Resistors and Ohm's Law

Multiple Choice
Which of the following is one function of a resistor in a circuit?
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Multiple Choice
According to Ohm's Law, what is the relationship between the current and the voltage across a resistor in a circuit?
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Multiple Choice
In a cylindrical resistor, what is the effect on the resistance if the radius of the vessel is halved, assuming the length and material remain constant? (The resistance $R$ of a cylinder is given by $R = ρ \frac{l}{π r^{2}}$ , where $ρ$ is resistivity, $l$ is length, and $r$ is radius.)
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Multiple Choice
Which of the following best describes Ohm's Law?
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Multiple Choice
Which of the following is the SI unit for electrical resistance?
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Multiple Choice
If a resistor has the color bands green, blue, brown, and gold, what is its resistance and tolerance?
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Multiple Choice
A resistor has a current through it of 5 A. If the EMF across the resistor is 10 V, what is the resistance of this resistor?
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Multiple Choice
Two resistors are made of the same material, one twice as long as the other. If the current through the shorter resistor is 5 A, what is the current through the longer resistor if they both have the same potential difference and cross-sectional area?
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Multiple Choice
A wire runs from the positive plate of a capacitor, into lightbulb 1, then out from lightbulb 1 directly into lightbulb 2. When lightbulb 2 is connected to the negative plate of the capacitor, what is true about the charge moving through the two lightbulbs?
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Multiple Choice
A copper wire with a radius of $2 . 0 mm$ and a length of $0 . 80 m$ is connected across the terminals of a $9.0 V$ battery. How much current flows in the wire?
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Multiple Choice
A certain wire has length L and radius r, and a resistance of R. That wire is melted down and the same volume of the same metal is used to produce a wire with length 2L. What is the resistance of the resulting wire?
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Multiple Choice
A copper wire and an aluminum wire have the same diameter. If the copper wire is $10 m$ long, how long is the aluminum wire if they have the same resistance?
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Multiple Choice
Which of the following is true about the change in potential across a resistor in a circuit?
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Textbook Question
A copper transmission cable $100$ km long and $10.0$ cm in diameter carries a current of $125$ A. How much electrical energy is dissipated as thermal energy every hour?
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Textbook Question
What is the resistance of a carbon rod at $25.8$ °C if its resistance is $0.0160 Omega$ at $0.0$ °C?
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