Assume that a negative charge is placed on the top plate of a capacitor.  A positive charge is placed on the bottom plate.  What is the magnitude of the electric field E between the plates?

You charge a piece of aluminum foil  (mass = 2.94 g)  by touching it to a charged rod. The charged rod gives the aluminum foil a charge of  −13 µC.  Your professor brings a charged plate over and tells you to put the aluminum foil on top of the plate. To your surprise the aluminum foil hovers motionless in the air above it! Calculate the value of the electric field from the charged plate (assume it is a uniform field and the aluminum foil is a point charge). magnitude      N/C direction      ---Select--- upward downward left right

A solid plastic ball has a radius of 6.0 cm and has a charge of +3.o nC ( in nano-Coulombs) that is uniformly distributed throughout its volume. Imagine there is a proton being held 1.5 cm away from the surface of the solid plastic ball, and then the proton is released. The proton will accelerate away from the ball, as we know, due to the repulsive electric force. Assuming the ball doesn't move, how fast is the proton moving when it is 5.5 cm away from the surface of the ball?

Liquid water has a large dielectric constant of ɛ, = 80. Suppose that a single sodium ion (Na+, carrying a positive charge of +1e) is held in the middle of a beaker of pure water. Compared to the volume of the sodium ion, the volume of the water can be effectively treated as infinite. a) Write down the electric displacement at r distance away from the sodium ion. b) Write down the electric field at r distance away from the sodium ion. c) Write down the electrostatic force that the sodium ion acts on a water molecule that is 2nm away from the ion and oriented with its dipole moment radially away from the ion. d) Calculate the polarization at a distance r = 2nm away from the sodium ion. e) The dipole moment of a water molecule is 6.17 x 10-30C · m. Estimate how much fraction of the water molecules that are at 2nm away from the sodium ion are reoriented by the sodium ion. (Assume that there are only two possible states for these water molecules: either randomly oriented and showing zero…

Two large parallel copper plates are 3.0 cm apart and have a uniform electric field between them as depicted in the figure. An electron is released from the negative plate at the same time that a proton is released from the positive plate. Neglect the force of the particles on each other and find their distance from the positive plate when they pass each other. (Note that you need not know the electric field to solve this problem.) A: _____________m

Two pieces of tape are stuck together, and then ripped apart, forming an electric dipole with one piece of tape at +0.20nC, the other at -0.20nC, held 3.0cm apart from each other. What is the electric field at a point positioned 10.0cm from the positive charge and 13.0cm from the negative? If a capacitor has an electric field with a magnitude of 1 microNewton/Coulomb exactly halfway between its positive and negative plates, which are each one square meter, then how much charge is on its positive plate? please provide correct significant figures in answer.

Long highway tunnels must have air cleaners to remove dust and soot coming from passing cars and trucks. In one type, known as an electrostatic precipitator, air passes between two oppositely charged metal plates, as shown. The large electric field between the plates ionizes dust and soot particles, which then feel a force due to the field. This force causes the charged particles to move toward and stick to one or the other plate, removing them from the air. A typical unit has dimensions and charges asshown. What is the electric field between the plates?

A particle with charge +4 nC (a nanocoulomb is 1 x 109 C) is located at the origin. What is the electric field due to this particle at a location m? 7 E = N/C