32 Answered Questions for the topic electromagnetism
A 4uC linear charge is distributed in a square of side 0.7m, which is contained in the 'yz' plane and has its center at the origin. The 'x' axis passes through the center of the square. Find the... more
Are radio waves and sound the same?
So the electromagnetic spectrum: radio waves, micro waves, infrared rays, visible light, ultra violet rays, x rays, gamma rays, cosmic rays. Now visible range is 390 to 700 nanometers, beyond 700... more
A scrapyard uses a big electromagnet to move around large metal objects such as cars and appliances. If the operator needed to drop a car to a new space, what would he need to do for this to... more
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. It consists of a solenoid (wire) wrapped around a bar of iron or other ferromagnetic material. A... more
Help with physic please ?
When AC is changed into DC to charge a laptop or phone, is the resulting voltage perfectly constant?A. YesB. No, but it can be made pretty closeC. No, in fact sometimes it's negative
Number of electrons as a function of time
Find the number of electrons as a function of time if: i(t) = 10 cos(t), to and q(to) = 0
EMF of a square conductor moving in homogeneous magnetic field
We have a homogeneous magnetic field of strength 1T.There is a copper SQUARE conductor, moving by constant speed 1m/s in a direction parpendicullar to magnetic field lines, so we can measure... more
for this coulomb's law question, why can't i solve by splitting e into Ex and Ey and then combining given Ey is zero? I get an answer 10^-30 instead of 10^-10.
The solution here says to figure it out by using cos theta as a factor, but I don't understand why I cannot just break it up into components? Figure shows two charge particles on an x acis -q on... more
Physics HW question
Two charges are placed on the x axis. One of the charges (q1 = +9.0 µC) is at x1 = +3.2 cm and the other (q2 = -24 µC) is at x2 = +8.1 cm.(a) Find the net electric field (magnitude and direction)... more
What is the total resistance of this circuit, and what type of circuit is this?
What is the total resistance of this circuit? And what type of circuit is this? I can’t tell if it’s parallel or series. (Physical science 10th grade) here is the link to the circuit diagram. ... more
Three Resistors are connected across a 24V battery in parallel. Find (a) Equivalent Resistance
Three Resistors are connected across a 24V battery in parallel. R1= 4Ω R2 = 8Ω R3 = 12ΩFind (a) Equivalent Resistance of the Circuit (b) Current in each Resistor
How does regenerative breaking work in ac 3 phase motors?
Please explain Regenerative breaking, where an induction motor can be used with a VSD and back feeds power to the VSD? How does is work does the motor act as a generator and create EMF or is it... more
What's the core difference between the electric and magnetic forces?
I require only a simple answer. One sentence is enough... (It's for high school physics)
Work done by the Magnetic Force?
The magnetic part of the Lorentz force acts perpendicular to the charge's velocity, and consequently does zero work on it. Can we extrapolate this statement to say that such a nature of the force... more
Why don't black holes form from forces other than gravity?
Gravity is the weakest of the fundamental forces, so what is so special about gravity that it can form an inescapably strong field while a force like the EM force cannot? It seems to me that if... more
What is the cause of the normal force?
I've been wondering, what causes the normal force to exist? In class the teacher never actually explains it, he just says "It has to be there because something has to counter gravity." While I... more
Are the field lines the same as the trajectories of a particle with initial velocity zero?
Is it true that the field lines of an electric field are identical to the trajectories of a charged particle with initial velocity zero? If so, how can one prove it? The claim is from a german... more
Two metal plates are squares of 12 cm by 12 cm, separated by 1.0 mm of air. Wires connected to each plate are also connected to a 9.0 V battery. After a long time, the battery is disconnected and... more
Are the Maxwell's equations enough to derive the law of Coulomb?
Are the 8 Maxwell's equations enough to derive the formula for the electromagnetic field created by a stationary point charge, which is the same as the [law of... more
How do electrons know when a circuit is closed?
I was told that electrons do not begin flowing unless the circuit is closed. The electrons from the battery are not in the ends of wire when it is open, apparently, as there is no reason for them... more
How can I stand on the ground? EM or/and Pauli?
There is this famous example about the order difference between gravitational force and EM force. All the gravitational force of Earth is just countered by the electromagnetic force between the... more
What causes 'positive' lightning to be rarer, higher charged, and longer lasting than 'negative' lightning?
Why is 'positive' lightning rarer, brighter, higher charged, and longer lasting than 'negative' lightning? Are there any other unique characteristics to positive lightning that sets it apart from... more