Terms & Objectives
The Indiana Physics Standards that Relate to Chapter 34 - Electric Current are:
- The Properties of Matter
- P.1.4 Employ correct units in describing common physical quantities.
- The Nature of Energy
- P.1.14 Explain the relation between energy (E) and power (P). Explain the definition of the unit of power, the watt.
- The Nature of Electricity & Magnetism
- P.1.18 Explain the concepts of ... electric current, electric potential, electric field ... Use the definitions of .... the ampere, the volt...
- P.1.19 Analyze simple arrangements of electrical components in series and parallel circuits. Know that any resistive element in a DC circuit dissipates energy, which heats the resistor. Calculate the power (rate of energy dissipation) using the formula Power = IV = I2R.
electromotive force (emf)
drift velocity (speed)
When you finish your study of electric current you should be able
- Tell what electric current is, and the units in which it is
commonly measured. (34.2)
- Describe the conditions necessary for current to
- Given a diagram of a bulb, wire, and a battery, tell whether
the bulb will be lit. (34.1)
- Name some common voltage sources. (34.3)
- Recognize electromotive force as a synonym for voltage.
- Tell what resistance is and what units are used to measure it,
and describe the factors that affect resistance. (34.4)
- Describe the relationship between current, resistance and
voltage in a simple circuit. (34.5)
- State Ohm's Law and tell what each of the symbols mean.
- Solve simple numerical problems involving: (34.5)
- Voltage (potential difference)
- Describe how an electric shock affects the human body.
- Discuss ways to avoid electric shock. (34.6)
- Discuss emergency procedures in case of electric shock.
- Describe the difference between DC and AC voltage and current.
- Tell whether household current is AC or DC and know the
nominal voltage and frequency. (34.7)
- Tell what a diode does in an electric circuit. (34.8)
- Describe how AC can be converted to DC. (34.8)
- Describe the motion of electrons in a DC or an AC circuit, and
discuss how energy is transported in a DC or an AC circuit.
- Tell where the electrons in an electric circuit
- Recognize that electric power equals current times voltage.
- Solve simple numerical problems involving: (34.11)
- Determine the cost to run an appliance given: (34.11)
- Power consumption of the appliance
- Energy cost per kilowatt hour
- Recognize the watt second and kilowatt hour as units of
Common Misconceptions to Correct:
In the study of electric current, it is very common for beginning
physicists to have the following misconceptions - do you? If so, you
need to put in some extra effort to discover why they are incorrect,
and correct them!
- WRONG! Electrons in an electric current move
at nearly the speed of light.
- WRONG! The electrons in an electric circuit are
supplied by the battery, generator, or wall outlet.
- WRONG! The energy in an electric current is carried by
last update April 3, 2008 by JL