User:Inconspicuum/Physics (A Level)/Electric Fields Questions

Electric Force
e = 1.6 x 10-19C


 * 1) A positron (charge +e) is 1 &mu;m from a lithium nucleus (charge +3e). What is the magnitude of the force acting on each of the particles? In what direction is it acting?
 * 2) An electron is 1mm from the positively charged plate in a uniform electric field. The potential difference between the plates is 20V, and the plates are 10cm apart. What force is acting on the electron? In what direction?
 * 3) The acceleration due to gravity around a point mass is constant, irrespective of the mass of the objects it is acting on. The acceleration due to electricity around a point charge is not. Use Newton's Second Law (F=ma) to explain this.
 * 4) An insulator contains charged particles, even though the overall charge on the insulator is 0. Why is the insulator attracted by a nearby charge?
 * 5) Where in the charged conducting plates which create a uniform electric field would you expect to find the charge located? Why?

Electric Field

 * 1) Two metal plates are connected to a 9V battery with negligible internal resistance. If the plates are 10cm apart, what is the electric field at either of the plates?
 * 2) What is the electric field at the midpoint between the plates?
 * 3) The charge on an electron is -1.6 x 10-19 C. What is the electric field 1&mu;m from a hydrogen nucleus?
 * 4) What is the direction of this field?
 * 5) A 2C charge is placed 1m from a -1C charge. At what point will the electric field be 0?

Electric Potential
&epsilon;0 = 8.85 x 10-12 Fm-1


 * 1) Draw a diagram of a uniform electric field between two plates, showing the field lines and the equipotentials.
 * 2) Do the same for the electric field around a point charge.
 * 3) The potential difference between two plates is 100V. What is the potential difference between a point halfway between the plates and one of the plates?
 * 4) What is the electric potential at a point 0.2m from an alpha particle (charge on an electron = -1.6 x 10-19C)?
 * 5) What is the electric potential energy of an electron at the negative electrode of an electron gun if the potential difference between the electrodes is 10V?

Electric Potential Energy
k = 8.99 x 109 Nm2C-2


 * 1) Convert 5 x 10-13 J to MeV.
 * 2) Convert 0.9 GeV to J.
 * 3) What is the potential energy of an electron at the negatively charged plate of a uniform electric field when the potential difference between the two plates is 100V?
 * 4) What is the potential energy of a 2C charge 2cm from a 0.5C charge?
 * 5) What is represented by the gradient of a graph of electric potential energy against distance from some charge?