Purpose This apparatus demonstrates electric field lines of a point charge by using a conductive test rod and rotating motion to produce a radial plume pattern that models field lines. Key benefits Visualizes the shape of electric field lines for a point charge, making abstract concepts concrete for students. Enables handson exploration of static electricity and electrostatic induction through simple setup and operation. Compatible with standard induction motors via wire connections, allowing controlled rotation and repeatable experiments. Sturdy components and silk thread permit sensitive, lowfriction response to induced charge distributions. Supplied as matching sets to support paired demonstrations or simultaneous student experiments. Each set is equipped with two. Main functions and components Demonstration of electric field line patterns: connect the bracket of the electric test feather to an induction motor by wires; rotating the motor causes the electroscope plumes to extend in a radial pattern that simulates point charge field lines. Components included: round base for stability, bracket to hold the test feather, conductive metal rod as the test feather, silk thread for delicate suspension, and related fittings. Conductive metal rod provides reliable charge transfer for clear plume response; silk thread minimizes mechanical damping so electrostatic effects are visible. Compatibility: designed for use with induction motors that can be connected by wires to the bracket assembly. How it works The conductive test rod mounted on the bracket is electrically coupled to a rotating motor. As the assembly rotates, electrostatic forces cause the plumes of the electroscope to move outward and assume a radial geometry, directly illustrating the expected fieldline pattern for a point charge. The motion and plume response allow students to observe the relationship between charge distribution and field geometry. Typical applications Classroom demonstration: Instructorled experiments to show fieldline geometry and the effect of rotation on charge distribution. Laboratory exercise: Student groups perform measurements and qualitative observations of static electricity and induction using the supplied sets. Science fair or outreach: Portable setup for visual demonstrations that explain electrostatic principles to a general audience. Why choose this apparatus Clear, repeatable visualization of electric field concepts without complex electronics. Simple setup and operation suitable for secondary and undergraduate physics curricula. Components focused on sensitivity and stability to produce reliable demonstration results. Contents reminder Each set includes the round base, bracket, silk thread, conductive metal rod, and related accessories. Each set is equipped with two.