6 Electricity and Magnetism 6.2 Capacitance, Dielectrics, Electric Energy, Storage
Capacitance of metal spheres and of a spherical capacitor
P2420300
U1 (measured voltage) as a function of U2 (charging voltage) measured on conducting spheres with three different diameters.
Principle
Wimshurst machine
Metal spheres with different radii and a spherical capacitor are charged by means of a variable voltage. The induced charges are determined with a measuring amplifier. The corresponding capacitances are deduced from voltage and charge values. Tasks 1. Determination of the capacitance of three metal spheres with different diameters. 2. Determination of the capacitance of a spherical capacitor. 3. Determination of the diameters of each test body and calculation of their capacitance values. What you can learn about ▪ Voltage; Potential; Charge; Electric field ▪ Electrostatic induction; Electrostatic induction constant ▪ Capacitance; Capacitor; Dielectrics
Function and Applications
Main articles High voltage supply unit, 0-10 kV Universal measuring amplifier Conductor ball, d 120mm Hemispheres,Cavendish type Multi-range meter, analogue High-value resistor, 10 MOhm Digital multimeter 2010
13670-93 13626-93 06238-00 06273-00 07028-01 07160-00 07128-00
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Historical device for generation of highvoltage to carry out many impressive electrostatic experiments. Equipment and technical data: ▪ Manually driven plastic discs and adjustable spark gap connected in parallel to two integrated Leiden bottles (high voltage capacitors) ▪ Diameter of disc: 30 cm ▪ Voltage: max. 160 kV ▪ Length spark gap: ca. 60 mm ▪ Dimensions (mm): 360 x 190 x 450 07616-00
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