Electric Fields Lesson Notes PDF

Disclaimer This presentation, including examples, images, and references, are provided for informational purposes only. Credits shall be given to the images taken from open sources and will not be used for any promotional activities. LESSON 1 Electric Charge Coulombs’ L...

Disclaimer This presentation, including examples, images, and references, are provided for informational purposes only. Credits shall be given to the images taken from open sources and will not be used for any promotional activities. LESSON 1 Electric Charge Coulombs’ Law Electric Field Electric Flux  ELECTRIC derived from the Greek word “Elektron” which literally means “Amber” The Structure of an Atom  Charge is QUANTIZED! All charge objects to date have a charge that is a whole-number of the charge of a single electron or proton.  Conservation of Electric Charge: The total charge in the universe is constant. No physical process can result in an increase or decrease in the total charge in the universe.  Before the Chemical Bonding +11 +17 -11 -17  After the Chemical Bonding +11 +17 -10 -18  Conductors: Allows charges to move freely Insulators: Charges are not free to move  Semiconductors: Can be made to behave sometimes as an insulator and sometimes as a conductor  Superconductors: Infinite conductivity to the flow of charge; current passes without losing energy at a critical temperature.  Coulomb’s Law “The magnitude between two points of the electric force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.  Coulomb’s Law 𝒒𝟏 𝒒𝟐 𝑭=𝒌 𝟐 𝒓 where 𝑵𝒎𝟐 𝟏 𝟗 𝒌 = 𝟖. 𝟗𝟗 × 𝟏𝟎 = 𝑪𝟐 𝟒πε𝟎 ε𝟎 = 𝒑𝒆𝒓𝒎𝒊𝒕𝒕𝒊𝒗𝒊𝒕𝒚 𝒐𝒇 𝒇𝒓𝒆𝒆 𝒔𝒑𝒂𝒄𝒆  Two-point charges with Q1=4.0μC and Q2=-2.0 μC are placed 3 cm apart. What is the force of attraction of these two-point charges?  𝒒𝟏 𝒒𝟐 𝑭=𝒌 𝟐 𝒓 = 𝟕𝟗. 𝟗𝟏 𝑵 Attractive Two-point charges with Q1=4.0μC and Q2=-2.5μC are placed to a charge Q3=+2μC 2.5cm 20degrees NE and 15degrees SE, respectively. What is the force of attraction of the two- point charge to the Q3?  ELECTRIC FIELD It is the amount of electric force per charge. Some Properties of Electric Fields  1. More field lines = stronger electric field. 1. More field lines and closer field lines means stronger electric field.  2. The lines start from a positively charged object and end on a negatively charged object. 3. The electric field lines must never cross. What is the magnitude of the electric field at a point 2 m from a point charge q=4 nC? An electric dipole consist of two equal but unlike charges separated by a distance. Two point charges, q1= 4.5 μC and q2= -4.5 μC, are separated by 6.4 cm. Find the E halfway between the pole.  References: Young and Freedman (2016). University Physics (14th ed.)Pearson Education Inc. Hewitt P. (2015). Conceptual Physics (12th ed.) Jim Smith. Walker J., Physics (2017). Physics (5th ed.)Pearson Education Inc. Serway and Jewett (2008). Physics for Scientist and Engineers with Modern Physics. (7th ed.)Thomson Learning, Inc.