/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 25 A resistor with \(R=30.0 \mathrm... [FREE SOLUTION] | 91Ó°ÊÓ

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A resistor with \(R=30.0 \mathrm{~S}\) and an inductor with \(L=0.600 \mathrm{H}\) are connected in series to a hattery that has emf \(50.0 \mathrm{~V}\) and negligible internal resistance. At time \(t\) after the circuit is completed, the energy stored in the inductor is \(0.400 \mathrm{~J}\). At this instant, what is the voltage across the inductor?

Short Answer

Expert verified
The voltage across the inductor at this instant is 20.0 V

Step by step solution

01

Determine the current

First, we need to determine the current flowing through the inductor. Since we know the energy stored in the inductor is 0.400 J and we have the expression for the energy stored in an inductor, we can arrange it to solve for the current: \(I=\sqrt{\frac{2U}{L}}\) This gives us the current, \(I\), as \(I=\sqrt{\frac{2*0.400 \mathrm{~J}}{0.600 \mathrm{~H}}}=1.0 \mathrm{~A}\)
02

Calculate the voltage across the resistor

Next, we can calculate the voltage drop across the resistor using Ohm's Law (V=IR). Plugging in our values gives us \(V_R=I*R=1.0 \mathrm{~A} * 30.0 \mathrm{~\Omega}=30.0 \mathrm{~V}\)
03

Calculate the voltage across the inductor

We know that the battery voltage is equal to the sum of the voltage drops across the inductor and the resistor (since they are in series): \(V=V_R+V_L\). Therefore, we can use this to solve for the voltage across the inductor: \(V_L=V-V_R=50.0 \mathrm{~V} - 30.0 \mathrm{~V}=20.0 \mathrm{~V}\)

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Resistor
A resistor is a fundamental component in electrical circuits. It limits the flow of electric current, helping to control the voltage and current in the circuit. The resistance is measured in ohms (Ω), and a resistor's ability to restrict current flow is quantified by its resistance value. Resistance in a circuit is crucial as it directly impacts how energy is distributed across other components, like the inductor.
For example, in our original exercise, a resistor with a resistance of 30.0 Ω is used. The resistor absorbs a portion of the voltage from the battery, resulting in a specific voltage drop across its terminals.
Ohm's Law
Ohm’s Law is a key principle in electrical engineering and physics, often expressed as:
  • \[ V = IR \]
where \( V \) is voltage, \( I \) is current, and \( R \) is resistance. This simple formula allows you to calculate the relationship between voltage, current, and resistance in any part of a circuit.
Applying this law to the given exercise, we can calculate the voltage across the resistor by multiplying the current, 1.0 A, by the resistance, 30.0 Ω, giving us a voltage of 30.0 V. This demonstrates how Ohm's Law provides a straightforward way to determine values in a circuit.
Series circuit
A series circuit is one where components are connected end-to-end, forming a single pathway for current flow. The same current flows through each component, and the total voltage around the circuit is the sum of the individual voltage drops across each component.
In the given exercise, the resistor and the inductor are in series with the battery. This setup ensures the current flowing through the resistor is the same as the current through the inductor. As such, the total voltage supplied by the battery is divided between the resistor and the inductor. This fundamental concept is why we can sum the voltage across the resistor and inductor to match the battery's emf.
Voltage across inductor
The voltage across an inductor in a circuit is determined by the changing current flowing through it. In our exercise, the battery's emf of 50 V is shared between the resistor and the inductor due to their series connection.
The voltage across the inductor can be calculated once the voltage drop across the resistor is known. Using the formula:
  • \[ V_L = V_{ ext{battery}} - V_R \]
we find the inductor's voltage as 20 V, after subtracting the resistor's voltage of 30 V from the battery's total voltage of 50 V. Understanding how to calculate this voltage is crucial for solving series circuit problems involving inductors.

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Most popular questions from this chapter

A toroidal solenoid has 500 turns, cross-sectional area \(6.25 \mathrm{~cm}^{2}\) and mean radius \(4.00 \mathrm{~cm}\). (a) Calculate the coil's self-inductance. (b) If the current decreases uniformly from \(5.00 \mathrm{~A}\) to \(2.00 \mathrm{~A}\) in \(3.00 \mathrm{~ms},\) calculate the sclf- induced emf in the coil. (c) The current is dirccted from terminal \(a\) of the coil to terminal \(b .\) Is the direction of the induced emf from \(a\) to \(b\) or from \(b\) to \(a\) ? $

A solcnoid \(25.0 \mathrm{~cm}\) long and with a cross-sectional area of \(0.500 \mathrm{~cm}^{2}\) contains 400 tums of wirc and carrics a currcnt of \(80.0 \mathrm{~A}\). Calculate: (a) the magnetic field in the solenoid; (b) the energy density in the magnetic field if the solenoid is filled with air; (c) the total energy contained in the coil's magnetic field (assume the field is uniform); (d) the inductance of the solenoid.

A long. straight solenoid has 800 turns. When the current in the solenoid is \(2.90 \mathrm{~A}\), the average flux through each turn of the solenoid is \(3.25 \times 10^{-3} \mathrm{~Wb}\). What must be the magnitude of the rate of change of the current in order for the sclf-induced cmf to cqual \(6.20 \mathrm{mV} ?\)

A \(35.0 \mathrm{~V}\) battery with negligible intemal resistance, a \(50.0 \Omega\) resistor, and a \(1.25 \mathrm{mH}\) inductor with negligible resistance are all connected in series with an open switch. The switch is suddenly closed. (a) How long after closing the switch will the current through the inductor reach onehalf of its maximum value? (b) How long after closing the switch will the energy stored in the inductor reach one-half of its maximum value?

Solar Magnetic Energy. Magnetic fields within a sunspot can be as strong as 0.4 T. (By comparison, the earth's magnetic field is about \(1 / 10,000\) as strong. ) Sunspots can be as large as \(25,000 \mathrm{~km}\) in radius. The material in a sunspot has a density of about \(3 \times 10^{-4} \mathrm{~kg} / \mathrm{m}^{3}\). Assume \(\mu\) for the sunspot material is \(\mu_{0}\). If \(100 \%\) of the magneticfield energy stored in a sunspot could be used to eject the sunspot's material away from the sun's surface, at what speed would that material be cjected? Compare to the sun's escape speed, which is about \(6 \times 10^{5} \mathrm{~m} / \mathrm{s} .\) (Hint: Calculate the kinetic energy the magnetic field could supply to \(1 \mathrm{~m}^{3}\) of sunspot material.)

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