Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Electrical resistivity and conductivity wikipedia , lookup
Time in physics wikipedia , lookup
History of electromagnetic theory wikipedia , lookup
Work (physics) wikipedia , lookup
Introduction to gauge theory wikipedia , lookup
Quantum potential wikipedia , lookup
Electric charge wikipedia , lookup
Aharonov–Bohm effect wikipedia , lookup
Chemical potential wikipedia , lookup
Physics E-1bx: Lecture 1 January 27, 2015 Activity 3: Electric potential and potential energy • We can summarize the previous activity as follows: The potential energy is equal to the mass times the gravitational potential. • Now we will define a quantity called the electric potential, which we will give the symbol V. It is also a scalar field, defined at every point in space: V(x, y, z) = the electric potential The SI unit for electric potential is the volt (V). • The electric potential is much like the gravitational potential. You can use it to find the potential energy: If an object has charge Q at a location where the electric potential is V, then the object has electric potential energy equal to: Uelec = QV 1. The SI unit of charge is the coulomb (C). Find an expression for volts in terms of coulombs and other basic SI units. (Hint: what is the SI unit of energy?) 2. You have a 9-volt battery. If you define the electric potential at the (–) terminal to be 0 volts, what would be the electric potential at the (+) terminal? (Not a trick question!) (+) (–) 3. Suppose we define the electric potential at the (–) terminal as –20 volts. Then what will be the potential at the (+) terminal? Does the value of the electric potential matter? 6