Download Mixed Problems for Electric Field, Potential, Capacitance, and

Mixed Problems for Electric Field, Potential, Capacitance, and Potential Energy 1. Draw the electric field between a. Two like charges b. Two unlike charges c. Two parallel plates of opposite charge 2. How is the direction of an electric field defined? 3. How is strength of an electric field indicated with electric field lines? 4. What happens to the size of an electric field if the charge on the test charge is halved? 5. What are the units of electric field? Capacitance? Electric potential? Electric potential energy? 6. Which has a larger capacitance, an aluminum sphere with a 1 cm diameter or one with a 10 cm diameter? 7. How can you store different amounts of charge in a capacitor? 8. An electron experiences a force of 0.20 N. What is the electric field intensity at that point? 9. An electron is located and x = 0.3 m and three protons are located at x = 0.5 m. What is the magnitude and direction of the field at the origin? 10. A 3 μC charge is located at y = 0.2 m and a ‐2μC charge is located at x = 0.5 m. What is the magnitude and direction of the electric field at the origin? 11. An electron experiences a 0.7 N force when it is 0.03 m from a charged object. a. What is the strength of the field at that point? b. What is the potential difference if the electron is brought from infinity to the point 0.03 m from the charged object? c. How much work is need to moves from infinity to the point 0.03 m from the charged object? 12. A proton is placed halfway between two oppositely charge parallel plates. The plates are separated by a distance of 0.5 m and there is a uniform electric field of 1500 N/C to the right. The proton is initially at rest a. What force does the proton experiences? b. What is the acceleration of the proton? c. How long does it take the proton to collide with one of the plates? d. What is the potential difference between the plates? e. How much work does the field do on the proton? f. What is the velocity of the proton before it collides with the plate? 13. A capacitor that is connected to a 45.0 V source contains 90.0 μC of charge. What is the capacitence? 14. Two parallel plates have a capacitance of 47 nF and have a potential difference of 54 V. What happens to the capacitance a. If the area of the plates is doubled? b. If the distance between the plates is doubled? c. If the potential difference is changed to 12 V? 15. How much energy is stored in a capacitor connected to 120 V and containing 5 C of charge? 16. How much energy is stored in a 35 pF capacitor when it is connected to a 12 V power supply?