Materials will be supplied to each group, including:

MOTOR - A single length of copper wire

BATTERY - A single 1.5V AA or similar battery

MAGNET - A single magnet

OPTIONAL - Metal bolt/screw (to use as a bearing to allow for rotation)

METHOD - Each team will be allocated a length of insulated copper wire max - 300mm length. Wind a coil leaving approximately 40mm at each end.

1. Example 1 Coil and paperclips
2. Example 2 Coil and paperclips
3. Example 3 Coil and paperclips

Circuit Design can be completed using only the materials supplied in the list above:

1. Students build an electric motor using only one battery. one magnet and one length of wire.
2. The circuit must include a, student built, pressure/touch switch' to turn the motor on/off.
3. Students must find a way to measure the speed / efficiency of the motor.
4. Students will appoint two judges.
5. The motor that is judged to have spun the fastest OR most efficiently will win.
6. The final score for each group will be the best of the three tries (at discretion of judges).
7. The judges decision is final.

• https://www.youtube.com/watch?v=y00fPzC-xiA

EXAMPLES:

• Other Simple homopolar motors
• Magnet information, safety and magnet care

BATTERIES:

• Common 1.5V battery sizes
  • AAA = 10.5D x 44.5L (0.41x 1.75“)
  • AA = 14.5D x 50.5L (0.57” x 1.99“)
  • C = 26.2D x 50.0L (1.03” x 1.97“)
  • D = 34.2D x 61.5L (1.53” x 2.42“)

• https://www.youtube.com/watch?v=r21ybCwXMjo
• https://www.youtube.com/watch?v=1zL8QLL6y7Y

Materials

ELECTRO-MAGNETIC POWER COIL - Each group will be given the a three meter length of 0.63mm enameled copper wire (the same length and type of wire for each group).

• The finished coil should have a diameter of 16 to 20mm - an approximate circumference of 60mm per turn - An AA size battery has a diameter of 14.5mm)
• A length of 50mm should be left out of the coil at each end (to allow for connection to a battery)
• The end of the coil can be looped twice around itself (to stop the coil unwinding when done).

METHOD - Students must design and build an electromagnetic power coil and momentary 'on' switch.

• The design of the coil will affect how efficiently it may power the test car. The design of the switch will also affect the efficiency of the coil. Factors effecting efficiency of coil include; Position, Turns, Length, Iron, Voltage ⁵⁾
• Both ends of the coil will need to connect to an electrical test circuit.
• The pressure switch will need to be activated for only a short period (1 second or less).

RULES: Each group may choose to power the 'default' test car or, alternatively, any one of the other designated test cars.

Each coil will be inserted into the experimental system and used to power the test car. The best of three runs will be counted.

The coil that has been measured and judged as powering an approved test car the farthest distance will win.

MAGNET SAFETY - Only a teacher or nominated adult may operate the test. Students must hand their power coil and switch to the teacher/ adult assistant for connection to the test rig.

The rocket car is fitted with Neodymium (rare earth) magnets.

It is very important to keep all metal objects at least 1 metre away from any of the cars and the test track.

Bringing magnetic items closer than 1 meter may result in serious injury. Don't do it!

Enamel Copper Wire Spool (100g):

• 0.63 = 36 metres
• 0.50 = 57 metres

Materials will be supplied to each group, including:

MOTOR - A single length of wire (cut into 3 pieces)

BATTERY - A single 1.5V AA or similar battery

METHOD = Find length of wire needed by converting winding form diameter to circumference calculator

Each team will be allocated a length of insulated copper wire, cut into three lengths:

THE TOTAL WIRE LENGTH FOR EACH MOTOR = 2,680mm

1. Wire length one 1850mm - 1 x base coil = 15 turns x 110mm circ. (D cell batt. 35dia = 1650mm) + 200mm spare = Sub-total
2. Wire length two 150mm - 1 x support wire = Sub-total
3. Wire length three 875mm - 1 x spinning coil = 15 turns x 45mm circ. (AA cell batt. 14.5mm = ) + 200mm spare = Sub-total

Common 1.5V battery sizes

• AAA = 10.5D x 44.5L (0.41x 1.75”)
• AA = 14.5D x 50.5L (0.57“ x 1.99”)
• C = 26.2D x 50.0L (1.03“ x 1.97”)
• D = 34.2D x 61.5L (1.53“ x 2.42”)

Circuit Design can be completed using only the materials supplied in the list above:

1. The circuit must include a, student built, pressure/touch switch.'
2. A motor built from only one battery and one length of wire (cut into three pieces)
3. Each group will be allowed up to three attempts
4. Students must find a way to measure the speed / efficiency of the motor.
5. The motor that is judged to have spinned the fastest or most efficiently will win.
6. The final score for each group will be the best of the three tries.

EXAMPLES:

• Ultimate DIY single wire motor
• Other simple motors

Purpose - To investigate the relationship between magnetic field inside a solenoid and the number of turns per metre of the solenoid;

To determine the value of the permeability of free space constant.

Introduction and Theory A solenoid is made by taking a tube and wrapping it tightly with many turns of wire. When a current passes through the wire, a magnetic field is present inside the solenoid. Solenoids are used to produce magnetic fields. They are seen in many electronic circuits, in magnetic resonance imaging machines in hospitals, etc.

In this activity, we will explore how the number of turns per metre affects the magnetic field inside the solenoid. A metal Slinky will serve as our solenoid. The Slinky represents a solenoid very well and is readily available. More importantantly, it is flexible so we can easily change the number of turns per metre.

We measure the magnetic field inside the Slinky by inserting a magnetic field sensor between the coils of the Slinky. The same measurements also allow us to calculate the permeability constant

• http://langaraphysics.com/1225slinky.pdf