Enquiring Minds Stage 3: Doing and Making

Motors

Physics

Specification

E / AQA / S / Edexcel / OCR Twenty First Century Science
E / OCR Gateway / E / WJEC

Enquiring Minds Stage 3: Doing and making

CBI: Team working – contributing to discussions

Problem solving – analysing facts and situations

Application of numeracy – practical contexts (eg measuring, weighing, estimating

and applying formulae)

Communication and literacy – clear, structured written work and oral literacy

Triple Science resources

Quick guide(s) / Training materials / e-learning asset/web link on triplescience.org.uk / Case studies
http://www.triplescience.org.uk/tripsci/Physics/magnetism/
Try ‘Electric Motors’
For info re motor effect, try ‘Electricity and Making Things Move’ / Physics case study Ravens Wood School: The motor effect

Keywords

Motor, electromagnetism, motion

How Science Works

1.1 Data, evidence, theories and explanations

c how explanations of many phenomena can be developed using scientific theories, models and ideas.

1.2 Practical and enquiry skills

a plan to solve a scientific problem.

How Science Works progression in this activity

Students are developing practical skills and appreciating how scientific knowledge can be used to explain the function of a simple device.

Learning objectives

Students will:

·  follow instructions to produce a working model of an electric motor

·  apply scientific knowledge to explore methods for altering the speed of the motor.

Learning outcomes

Students will be able to produce a working electric motor.

Key concepts/knowledge/skills/understanding addressed by this activity

·  The interaction of an electric current and a magnetic field can result in motion.

·  Altering the current flowing, the number of coils or the strength of the magnetic field are common ways of altering motor effects.

Assessment opportunities in this activity

There are opportunities to assess students’ manipulative skills and problem solving.

How ICT is used to support learning

Students can use websites to see how to build their motors.

Overview of activity

Students build a single pole motor to illustrate their understanding of the motor principle. Because resources are simple, this project can be extended to investigate the effect of number of turns, strength of magnetic field, etc.

Activity in detail

Activity title

Building a simple homopolar electric motor
Begin by recalling previous work on the interaction of electric currents and magnetic fields to describe and explain the motor effect.
Most schools will have the ‘standard’ motor kit, but variables are hard to control or alter. Here, students can use their imagination to adjust their motors, possibly working individually or in small groups.
The following two sites show how to build a single pole motor:
http://fly.hiwaay.net/~palmer/motor.html
http://scitoys.com/scitoys/scitoys/electro/electro.html - single
A different model is available from http://www.evilmadscientist.com/article.php/HomopolarMotor
Students build a model quickly and may try to explain the process by which it works. They may be able to change various parts, depending on which model they make. It may also be possible to use an electromagnet rather than a permanent magnet, allowing more variables to be considered.
Some students might like to extend this work to include extra brushes.
This activity could be of interest for an extended project or a science club.

Opportunities to differentiate learning

By input – some students may need help with building the motors; some may find removing the insulation particularly difficult.
By outcome – quality of creative work, depth of scientific exposition if required, ability to extend to more complex models.

Risk assessment

Main hazards identified / Who would be affected? / Control measures to reduce risk
Sharp implements used for cutting or removing insulation
Overheating of wire / Any student participating
Any student participating / Warn students not to misuse equipment
Have bench protectors
Warn students to beware of hot wire and to switch off quickly if problems occur

Resources

Insulated copper wire, bare copper wire (or other method of building ‘brushes’), magnet, power supply or cell, insulating tape
http://resources.schoolscience.co.uk/CDA/14-16/physics/index.html
Other websites explaining how to make simple dc motors include
http://fly.hiwaay.net/~palmer/motor.html
http://scitoys.com/scitoys/scitoys/electro/electro.html - single
A different model is available from http://www.evilmadscientist.com/article.php/HomopolarMotor
A reminder of the motor principles may be taken from
http://www.antonine-education.co.uk/Physics_GCSE/Unit_3/Topic_7/topic_7.htm