# What is elecromagnetism: Definition and 7 Discussions

Electromagnetism is a branch of physics that deals with the study of electromagnetic force, which is one of the fundamental forces of nature. It includes the interactions between electric charges, electric fields, magnetic fields, and their effects on matter.
1. ### Find the field inside and outside a spherical geometry

So I tried to solve this using the Hertz potentials. I choose the magnetic one since this one corresponds to the magnetisation. Before I start let me note that I denote a unit vector with a hat, while ##{x,y,z}## are the Cartesian coordinates and ##{r,\theta,\phi}## are the spherical...
2. ### Experiment measuring the distance dependence of a suspended metal bolt from a magnet

My set-up is the following: i have an iron bolt suspended on a string next to an electromagnet, of which I steadily increase the voltage and thereby the magnetic field. Supposing the force is linear with the magnetic field and dependent on the distance between the bolt and magnet. The exact...
3. ### B Antenna induction, oscillating circuit generating EM Waves

Hello! Now i need a bit explanation, so "oscillating circuit" capacitator + coil in series. Let's look at this as infinite, without any loss. We get changing magnetic field and electric field. Capacitator discharges, current goes to coil increasing its magnetic field, then starts magnetic field...
4. ### I Reason for Opposite Signs for Terms in Faraday's Law and Ampere's Law

Hello, im a bit confused about the right term in Faradays Law vs the right most term in Amperes Law. They both seem like terms corresponding to a resistance to change, similar to inertia. As in, the induced electric field from a changing magnetic field has an opposite direction compared to the...
5. ### Calculations involving different Dielectrics and Capacitors

TL;DR Summary: Need dielectric constant for given capacitor Given a 7.4 pF air-filled capacitor, you are asked to convert it to a capacitor that can store up to 7.4 mJ with a maximum potential difference of 652 V. Which dielectric in Table 25-1 should you use to fill the gap in the capacitor...
6. ### B Questions about the Universe: Positive & negative fields and effects

So I saw an article about the universe and lets say the article saied: the essence of the universe, which is impossible, as it has been proven that universal constants such as the gravitational constant and the speed of light indicate the existence of unified physical laws that govern the entire...
7. ### Voltage and effective resistance of an infinite lattice of resistors

The reasoning I had was that in the horizontal direction, if the current flows into a node from the left, then it must flow into the node on the right so that that node has current flowing in from the left. Thus, the flow on the horizontal is always either from left to right or from right to...