Homework Statement
The object in the figure below is midway between the lens and the mirror, which are separated by a distance d = 24.9 cm. The magnitude of the mirror's radius of curvature is 20.4 cm, and the lens has a focal length of -16.5 cm.
(a) Considering only the light that leaves the...
I guess I can somewhat see how it's in series, but this doesn't make much sense to me.
This is basically an equivalent circuit after the voltage source is removed, but I can't make sense of this. They're in series, but what happens to the current? Does it go back towards the capacitor?
Homework Statement
The circuit in the figure below has been connected for a long time. Let R1 = 8.20 Ω and R2 = 4.40 Ω.
(a) What is the potential difference across the capacitor?
(b) If the battery is disconnected from the circuit, over what time interval does the capacitor discharge to...
So what should I use to find the current using that voltage? The capacitor would start discharging. Is it the electrons we care about here rather than the actual "current"? Because the electrons would go through R2. The "current" doesn't go through anything.
The weird thing about these problems...
So the potential of the capacitor has to be equal to ε right? What would I do with that, though? Find the charge? I'm not sure how that would be useful.
Also, I think I have some misunderstanding here that might be causing my problem. Immediately after the switch is turned on, wouldn't it still...
This is kind of what I'm struggling with. Maybe I'm overthinking this. I'd consider the situation right as the switch is closed. That would give me the initial current, but I'm not really sure what to do. Maybe I'm just lacking context of what's going on.
Now that I think about it, after a long...
Homework Statement
In the circuit of the figure below, the switch S has been open for a long time. It is then suddenly closed. Take = 10.0 V, R1 = 56.0 kΩ, R2 = 200 kΩ, and C = 14.5 μF.
(a) Determine the time constant before the switch is closed.
(b) Determine the time constant after the...
I see. Looking at my notes now, my teacher proved this (I think) using Ampere's law. Is that a valid way? Here's how I did it:
But this doesn't seem to take into account the length.
Yeah, I see what you are saying. There is already a formula to find the magnetic field of a long straight wire, so I just combine it with the circular field at that point and get the answer.
So here's the thing I don't get though.
Let's take this straight wire and say it has an infinite...
Okay, so I think I'm missing something really basic.
So basically, at that point, we are adding the magnetic field due to the circle, AND due to the straight wire? I've been very confused about this because I thought there were two separate magnetic fields from the same wire. Assuming this is...
Homework Statement
A conductor consists of a circular loop of radius R and two long, straight sections as shown in the figure. The wire lies in the plane of the page and carries a current I.
(a) What is the direction of the magnetic field at the center of the loop?
(b) Find an expression for...
Homework Statement
In the figure below, suppose the switch has been closed for a time interval sufficiently long for the capacitor to become fully charged. (Assume R1 = 11.0 kΩ, R2 = 22.0 kΩ, R3 = 4.00 kΩ, and C = 11.0 μF.)
(a) Find the steady-state current in each resistor.
(b) Find the...
P=IV, so solving for voltage V=P/I. We don't know what I is, so we plug in V=IR, or I=V/R. Then we get V2=PR2. Plugging in the values, we get that the voltage drop across R2 is 126.89V.
So from then we could easily find the current at that place, but that would only be that part of the current...