Download ELECTRICITY AND MAGNETISM LAB

ELECTRICITY AND MAGNETISM LAB
(These laboratory experiences are adapted from the Conceptual Physical Science
Laboratory Manual)
Introduction
Electricity and magnetism are the foundation of today's modern society. We rely on
electricity and magnetism to provide us with light, start our cars, and run our computer.
Today's laboratory is an exploratory lab to develop a qualitative feel for the two basic
electrical circuits, series and parallel, and magnetism.
Science Information
For electrical current to flow in a wire or electrical device a potential difference
(measured in Volts) must be established between the two ends of the wire. One of the
simplest devices for establishing a potential difference is to use a battery. In many ways a
potential difference is like having a waterfall. The water will fall from a higher area to a
lower area. In the process the water can do work.
For example, a 1.5V battery can provide 1.5 Joules of energy for each Coulomb of charge
that moves through the circuit. This energy can be used to light lights or ring buzzers.
The two slots in a wall socket have a potential difference of 120 V or 120 J per Coulomb
of charge. This can be used to run computers or toasters.
The first part of this lab looks at how the current is distributed in an electrical circuit. In
the second part you will examine distribution of energy in different (series and parallel)
bulb arrangements. For this purpose you will use a hand cranked generator to produce the
potential difference to power the light bulbs. The generator converts mechanical energy
(Work done = Force x Distance) into electrical energy as you turn a coil of wire in the
presence of a magnetic field.
Closely related to the study of electricity is the study of magnetism. In the third part of
the lab you will observe the different configurations of a magnetic field. The magnetic
field itself is result of the motions of electrons around the atoms of (so called
ferromagnetic) elements like iron. Moving electrical charges produce magnetic fields.
Part I: Batteries and Bulbs
Discussion
Many devices include electronic circuitry, most of which are quite complicated. Complex
circuits are made, however, from simple circuits. In this activity we build one of the
simplest yet most useful circuits ever invented for lighting a light bulb! To the right are
common elements found in electric circuits. It is common to call a single cell a battery,
but strictly speaking, a battery refers to a combination of cells. So instead of saying "a
battery of cells," we simply say "a battery."
Follow procedures related to part I in the answer template. Answer associated questions.
Part II: Cranking Up
Purpose
To compare qualitatively the power inputs to a series and to a parallel circuit.
Discussion
Here's a chance to both see and feel some differences between series and parallel circuits.
Follow procedures related to part II in the answer template. Answer associated questions.
Part III: Magnetic Personality
Purpose
To explore the influence of a moving magnet in a coil of wire--electromagnetic induction.
Follow procedures related to part III in the answer template. Answer associated
questions.
Part IV:
Explain how are parts II and III related
Key Terms: electrons, electric current, voltage, resistance, electric circuit, parallel circuit,
serious circuit, magnets, magnetism, electric power, voltage source, battery, conductor,
resistor, bulb, electric generator, induced current, Ampere, Volt, Ohm.