Inductor in simple circuit w/ graph Problem Help

The question asks what the rate of change of current will be at a specific time when the switch is closed. The equations L=flux/current, emf=L|di/dt|, and emf=|d(flux)/dt| are mentioned, but the person is unsure how to interpret the graph and find the flux of each turn. They also question if the slope of the graph is just (d(flux)/dt)/(di/dt).
  • #1
SWFanatic
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0

Homework Statement


In Figure 30-63, the inductor has 26 turns and the ideal battery has an emf of 16 V. Figure 30-64 gives the magnetic flux through each turn versus the current i through the inductor. If switch S is closed at time t = 0, at what rate di/dt will the current be changing at t = 1.9L?
Figure 30-63 is a simple circuit with a battery, resistor, switch, and inductor.
Figure 30-64 is a flux vs. current graph, with a constant slope of 2E-4H.


Homework Equations


L= flux/ current
emf = L|di/dt|
emf = |d(flux)/dt|


The Attempt at a Solution


I am rather lost. The graph shows flux per turn over current, but how do I know what the flux of each turn is? The graph is just an increasing slope with seemingly no boundries. Also, isn't the slope just (d(flux)/dt)/(di/dt)? And if so, wouldn't (di/dt) just be 1, or have I forgotten how to read graphs? Thanks for any help.
 
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  • #2
I can't see any pictures
 
  • #3


As a scientist, it is important to carefully read and analyze the given information before attempting to solve the problem. Let's break down the given information and equations to better understand the problem.

The circuit in Figure 30-63 consists of a battery, resistor, switch, and inductor. When the switch is closed at t=0, the inductor will start to build up a magnetic field, causing the current to increase. The battery has an emf of 16V, which is the potential difference that drives the current through the circuit.

Figure 30-64 shows the relationship between the magnetic flux through each turn of the inductor and the current through the inductor. The slope of the graph, which is a constant 2E-4H, represents the inductance of the inductor (L). This means that for every 1 ampere (A) of current flowing through the inductor, there is a change in magnetic flux of 2E-4H (Henry).

Now, let's look at the equations provided. The first equation, L= flux/current, is the definition of inductance. It tells us that the inductance of the inductor is equal to the magnetic flux through each turn divided by the current. The second equation, emf = L|di/dt|, is known as Faraday's law and tells us that the induced emf (voltage) in the inductor is equal to the inductance multiplied by the rate of change of current. Finally, the third equation, emf = |d(flux)/dt|, is another way of stating Faraday's law, where the induced emf is equal to the rate of change of magnetic flux.

Now, to solve the problem, we need to find the rate of change of current (di/dt) at t=1.9L. This means that we need to find the slope of the current vs. time graph at t=1.9L. To do this, we can use the slope formula, which is rise/run. In this case, the rise is the change in current (di) and the run is the change in time (dt). Therefore, the slope (di/dt) at t=1.9L is equal to the change in current divided by the change in time.

To find the change in current, we can use the slope of the graph, which is 2E-
 

1. What is an inductor in a simple circuit?

An inductor is a passive electronic component that stores energy in the form of a magnetic field. It is typically made of a wire wound into a coil and is used in circuits to store and release energy as needed.

2. How does an inductor affect the flow of current in a simple circuit?

An inductor resists changes in the flow of current in a circuit. This means that when the current in a circuit is increasing, the inductor will try to limit the increase by storing some of the energy in its magnetic field. Conversely, when the current is decreasing, the inductor will release the stored energy to try to maintain the current flow.

3. What is the symbol for an inductor in a circuit diagram?

The symbol for an inductor is a coil or spiral shaped symbol, usually labeled with the letter "L". It is placed in series with other components in a circuit and can be found in various electronic devices such as radios, amplifiers, and power supplies.

4. How is the inductance of an inductor measured?

The inductance of an inductor is measured in units called henries (H). This measurement is determined by the number of turns in the coil, the material of the core, and the physical size and shape of the inductor. Inductance can also be affected by the frequency of the current passing through the inductor.

5. Can an inductor be used in both AC and DC circuits?

Yes, an inductor can be used in both AC (alternating current) and DC (direct current) circuits. In AC circuits, the inductor's ability to resist changes in current flow is utilized to create a phase shift in the current. In DC circuits, the inductor can act as a temporary energy storage device, similar to a capacitor, and help to smooth out fluctuations in the current.

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