My PBL Project

Driving Question:

The driving question behind my project is "How does the Wimshurst machine produce a charge?" First, it's important to look closely at the device. As you can see, each metal sector moves very close to the collection comb. When the disks start to turn, the metal segments rub against the brushes. This rubbing effect creates an electric charge in each metal segment, which is transferred through induction to the Leyden jars. According to the Conservation of Energy principle, mechanical energy from you turning the wheel is changed into electrical energy

Introduction:

The student uses a systematic approach to answer scientific laboratory and field investigative questions. The student is expected to demonstrate the use of course apparatus, equipment, techniques, and procedures, including ... discharge tubes with power supply (H,He,Ne,Ar)... electrostatics kits... [and] cathode ray tubes... The student knows the nature of forces in the physical world. The student is expected to identify examples of electric and magnetic forces in everyday life: investigate and describe the relationship between electric and magnetic fields in applications such as generators, motors, and transformers.

Materials:

• • Wimshurst machine,

  • patch cords or other wire,

  • alligator clips or wire connectors,

  • charging sphere,

  • electric whirl,

  • rubber and metallic balloon,

  • aluminum foil,

  • string,

  • a doll with hair or electrostatic plume,

  • Volta's Hail Storm,

  • Leyden jar capacitor,

  • Lightning plate,

  • Neon wand,

  • Cathode ray tube

Procedure:

The wimshurst machine spins to produce electricity and electrostatic, basically as a windmill does. You should spin the handle on the machine fast until electromagnets produce a "zap".

Scientific Principle:

A Wimshurst machine develops a maximum electrostatic based on the number of plates used and their diameter, and the spacing between the plates. Increasing the rotating speed of the plates does not increase the maximum discharge voltage it only decrease the time the machine takes to gain its full electrostatic potential.