1. ### Position for maximum electric field between two wires

For the first part, since $$E(r) \propto \frac{1}{r} \hat{r}$$ by the principle of superposition the maximal electric field should be halfway in between the two wires. Then I'm not sure how to go about the second part of the question. I understand that the total potential due to the two wires...
2. ### B EMF vs Potential difference

Is emf the work done to move a positive charge from LOWER potential to HIGHER potential to maintain the potential difference or else the charges move from higher potential to lower potential and will reach a point where the potential is the same between the two points and the charge will stop...
3. ### Determine the Electrical potential at a given point

A rod with a circular center in the middle (which causes the rod to change direction by 90 °) has an evenly distributed linear charge density 𝜆 of electrons along the entire rod. Determine the electrical potential of the red dot in the figure below which is at the center of the circular round...
4. ### Circuit Analysis of a diagram with series and parallel circuits

I found the Req which is 13.6 and also found the It which is 0.74. I'm having trouble finding the separate current and potential difference numbers.
5. ### I Electric field in a circuit with a DC source

So I understand that when an electric field is produced in a conductor of length L, the net electric field in the conductor will be 0 because the rearrangement of electrons in the conductor results in the production of its own electric field which cancels out the one produced initially...
6. ### Potential difference in a 2 disk system (Capacitor)

Homework Statement A capacitor consists of two large metal disks placed a distance ##s## apart. The radius of each disk is R ## (R \gg s)## and the thickness of each disk is ##t##. The disk on the left has a net charge of ##+Q## and the disk on the right has a net charge of ##-Q##. Calculate...
7. ### Final potential difference of a 2 capacitor system

Homework Statement An isolated parallel-plate capacitor of area ##A_1## with an air gap of length ##s_1## is charged up to a potential difference ##\Delta V_1## A second parallel-plate capacitor, initially uncharged, has an area ##A_2## and a gap of length ##s_2## filled with plastic whose...
8. ### I Floating potential of a conductor in an electrical field

I'm interested in the following general question: Assume x,y,z is an axes system, and that the y-z plane is occupied by a conductive plate at a known potential V with respect to the earth. Now, a conductive material M of neutral global electrical charge is placed at some distance of the plate...
9. ### Gravitational Potential Reference Point

Can someone please show that calculation of gravitational potential energy at a point R+h from the centre of the earth by choosing the centre of the earth to be at zero potential. Here R is the radius of the earth and h is not very small wrt to R
10. ### Which way do I measure the potential difference

Homework Statement All the bulbs in the circuits are identical, as are all the batteries. Rank the magnitude of the potential difference between points M and N. Homework Equations V=IR The Attempt at a Solution My most fundamental question is actually which way do I know to take the...
11. ### What is the potential of plate B with respect to infinity?

I have two isolated plates A and B, kept parallel to each other. Now I give charge +Q to the plate A, it will redistribute itself as +Q/2 on the outer plate A and + Q/2 on the inner plate A. Right? Now this will induce charge -Q/2 on the inner plate B and +Q/2 charge on the outer plate B...
12. ### Potential and Electric Field

Homework Statement A potentially silly question that I have put off too long to ask, any assistance is greatly appreciated! The electric field evaluated along the Z axis of a ring of charge centered on the origin and lying on the XY plane is only a function of ##z## and points only along...
13. ### Potential Difference/Voltage-Graph Help Needed (Long)

Homework Statement Alright, this is a Lab Exercise, so it's light on an actual introduction and data, but I'll do my best to put into words the whole thing. The gist of it is that we have a Vat with water, a millimetre paper at the bottom, and we put two Equipotential surfaces inside. We charge...
14. ### Parallel plate electric fields -- # of electrons transferred

Homework Statement An oil droplet is suspended between two horizontal parallel plates with a separation of 0.4 cm. If the potential difference of 320V is applied to the plates, determine the number of electrons transferred to/from the droplet. Given/Known Values mdroplet = 5.2×10-6 kg d = 0.4...
15. ### Confirming my logic on potential difference

Homework Statement You’ve decided to protect your house by placing a 5.0 m tall iron lightning rod next to the house. The top is sharpened to a point and the bottom is in good contact with the ground. From your research, you’ve learned that lightning bolts can carry up to 50 kA of current and...

So I understand that a capacitor consists of 2 plates separated by a distance which creates a potential difference between the plates. But I was confused, when watching this physics video it seemed to be saying that once the capacitor was fully charged, the plate closest to the positive terminal...
17. ### I Voltage in terms of a battery

I'm trying to understand what exactly it means in terms of the voltage of a battery. I know that the voltage in a battery is just the potential difference between the two terminals. But, is the negative terminal used as a relative point and seen as 0? If that's the case does 12V mean that the...
18. ### Potential Difference b/w concentric shells -- confusion

Homework Statement :[/B] This is isn't exactly a problem,but actually something i don't understand in the book i was following, so there this art. about 'Principle of a Generator', whose description is given as, " A generator is an instrument for producing high voltages in the MeV range. Its...
19. ### Magnetic Fields- Finding the radius

Homework Statement A single ionized uranium ion of mass 6.9 x 10 ^-25 kg is accelerated through a potential difference of 4.4 x 10^5 V. What is the radius of the path it would take if injected at 90 degrees into 0.47 T uniform magnetic field at this velocity? 3. Attempts Since centripetal...
20. ### Potential difference between two points

Homework Statement Question from OCR A Level Physics Exam 2014 (i) and (ii) = definitions (iii) = explanation (iv) = P.d. at 6Ohm Resistor = 0.48V (v) Suggest why the p.d. between X and Z is zero Homework Equations I don't think there are any The Attempt at a Solution I couldn't...
21. ### Why do the capacitors in this circuit have the same voltage?

Homework Statement Homework Equations C = Q/V The Attempt at a Solution I understand that capacitors in parallel have the same voltage, but wouldn't they be in series after the switch is flipped, since no current goes to the left most portion of the circuit.
22. ### B How to remember what happens to I, V and R in a circuit?

There are two circuits, each consist of a cell and two bulbs, in one circuit they are in parallel, and in the other they are in series. What's the best way to remember which lamp has the greatest pd, current and resistance when one bulb is brighter than the other in the series and parallel circuit?
23. ### Need help understanding potential difference practically

I have a problem understanding the concept of potential difference. I get the picture of seeing it as a height difference for example (rock or water that would fall down) but what confuses me is that many times the order of elements in a circuit does not matter. To explain myself better: if I...
24. ### B Ohm's law

According to Ohm's law, "Physical conditions remaining the same, the electric current flowing through a conductor is directly proportional to the potential difference across the two ends of the conductor" I have two conceptual queries: FIRST When the ends of the conductor are not connected to...
25. ### I Oscillating Electron Beam potential between metal plates

Take the case where the electron-beam is oscillating between two parallel metal plates, there will be alternating potential developed between the plates as metal tries to negate all external electric fields. My query is, (1) How to calculate the potential developed and possible way to simulate...
26. ### Equivalent capacitance of a system from potential difference

Homework Statement Calculate the equivalent capacity of the capacitor system between points ##x## and ##y## Homework Equations ##C=q/V## The Attempt at a Solution I'm asking about this problem because I know how to calculate ##V_x-V_y##, but I don't know how can I extract the equivalent...
27. ### Calculate the deflection sensitivity in mm per volt

Homework Statement Describe a method by which the charge / mass ratio e / m of the electron has been determined. Calculate the deflection sensitivity (deflection of spot in mm per volt potential difference) of a cathode ray tube from the following data: electrons are accelerated by a...
28. ### Calculate the speed of the electrons as they enter the gap

Homework Statement Two parallel metal sheets of length 10 cm are separated by 20 mm in a vacuum. A narrow beam of electrons enters symmetrically between them as shown. When a PD of 1000 V is applied between the plates the electron beam just misses one of the plates as it emerges. Calculate...
29. ### Find drift velocity of the current carriers in the copper strip

Homework Statement ABCD is a plane rectangular strip of conducting material of uniform thickness, with a steady current flowing uniformly from AD to BC. The potential difference between E and F, the mid-points respectively of AB and CD, is zero, but when a magnetic field is set up at right...
30. ### Potential difference of helium nucleus question

Homework Statement What potential difference is needed to give a helium nucleus (Q = 3.2 × 10-19 C) 50 keV of kinetic energy? Homework Equations V=U/Q 3.2 × 10-19 C = 2e The Attempt at a Solution I was quite sure I had the right answer but it keeps saying I'm wrong? V = (50*10^3 eV) / 2e =...