Electricity and Magnetism Answers

4.1 What are the significant physical differences between Poisson’s and Laplace’s equations.

4.2 The flux of an electric field is given by Gauss’s Law: ∇ ∙ 𝑬 = 𝜌 𝜀0 . Use this to determine Poisson’s equation. (Hint: what is the Laplacian of the potential field 𝜙?) 

when a positively charged rod is brought near an isolated neutral conductor without touching it, will the rod experience an attractive force, a repulsive force, or no force at all

Use the capacitance meter to view the capacitance of the device. Which of the controllable parameters effect the capacitance?

Using the stored energy meter, determine which of the controllable parameters effect the stored energy.

Using the plate charge meter, determine which of the controllable parameters effect the plate charge.

Set the battery voltage to +1.5 volts, the plate separation to 5.0 mm, and the plate area to 100.0 mm 2 . Calculate the capacitance, plate charge, and stored energy to verify that the values match those shown on the meters.

Now switch the simulation to the lightbulb experiment. Use the battery to charge the capacitor and then the switches to discharge it through the lighbulb. Perform this discharge experiment several times, each time with the same battery voltage but a different plate separation. What do you notice

about the discharge cycle time when the plate separation is different?

https://phet.colorado.edu/sims/html/capacitor-lab-basics/latest/capacitor-lab-basics_en.html

The area of ​​the winding loop is a square with a side length of 1.2 m and 10 turns and a current of 1.1 A. How much torque is caused by the Earth's magnetic field when the axis of symmetry of the winding (plane normal) is directed a) to the west? b) to the north?

The magnetic flux density of the Earth's magnetic field is 50 μT, the inclination is 73º and the declination is 0º.

A magnetic field is produced inside a cubic chamber of volume A and the electromagnetic waves propagate at the speed of light C. If some other particle is present in this chamber, list the four conditions under which this particle of mass m will experience a force-free "life".

Suppose we make for our Physics Laboratory a 10 micro-Henry inductor by wrapping a 0.030 cm diameter wire around a 4.0 mm diameter cylindrical core. How long must this core be?

You have a 12V battery connected to a single straight nichrome wire in your heater. If the wire is a millimeter thick and a meter long, and you place a device that measures magnetic field strength at a one-centimeter distance away from the wire, what will be the reading on this device?

Consider a thin, straight wire carrying a constant current I and placed along the y-axis as shown in Figure. Determine the magnitude and direction of the magnetic field at point P on x axis due to this current if the direction of current is in y axis.