Electricity and Magnetism Answers

4 point-charges (same magnitude, signs shown) are arranged in a
square. At which one of the "mid-points" (A, B, C) is the net electric
field zero?

If a metal plate of thickness 't'm is kept between two equal charges and the seperation between the charges is 'r'm. Find the Electric Field Intensity, 'E'.

Find the magnitude of the polarization vector P in a dielectric material with r = 2.8 if D = 3.0 X 10-7 dC / m2.

charges q1=0.09 C, q2=0.01 C, are a distance /=1m apart. a charge Q is held fixed on the line between them, a distance x from q1. what value must Q,x have for q1,q2 to feel no net force?

A -15nC point charged is placed on the x-axis at x =1.5m. and a -20nC charge is placed on the y-axis at y = -2.0m. what is the magnitude of the electric field at the origin?

A -2.0nC point charged is placed at one corner of a square(1.5m on a side).and a -3.0nC charge is placed on a corner-diagonally away from the first charge.what is the magnitude of the electric field at either of the two unoccupied corners?

The potential energy of a 3.0 x 10 C charge changes from 0.02 j to 0.08 j when it is moved from point 1 to point 2. Calculate the change in the electric potential between these two points

I can’t believe that after all these problems you are still making things! It’s great for
me, because I get to have you do calculations on them. This time, you are making a
solenoid. Naturally, you use a toilet paper tube.3 The tube has a diameter of 4.00 cm
and a height of 11.2 cm. You wrap it with copper wire having a cross-sectional area
of 1.02 × 10−6 m2
(20-gauge; note that the resistivity of copper is 1.70 × 10−8 Ωm ).
Your resulting solenoid has 98 loops. Determine (a) the current required to produce a
magnetic field of 6.00 mT in the center of the solenoid, and (b) the power required to
deliver this magnetic field.

In an odd twist of events, I lack a ruler but do have a pair of wires, a power supply,
and an ammeter. I know that if I run a current through the wires I can balance the
downward force of gravity on the top wire with the repulsive magnetic force between
them. I know the weight per unit length of the wires is 0.15 N/m. I can use the power
supply and the ammeter to choose the current (assumed to be the same current in
each wire). What value of current should I choose to make the distance between the
two wires equal to exactly 1.00 cm? Note that these are parallel wires and not a single
wire in an external magnetic field.

An electron moving parallel to the x-axis has an initial speed of 3.70×(10)^6 m/s at the origin. It's speed is reduced to 1.40×(10)^5 m/s at the point x=2c.m
-calculate the electric potenial difference between the origin and that point?