This is a brief description of the components of the current balance apparatus, as well as instructions for its use. The figure below shows the different components of the apparatus.

• A, B: Connections for power to upper tilting wire
• C, D: Connections for power to lower wire
• E, F: Adjustable weights for balancing tilting wire
• G: tilting, U-shaped wire
• H: lower straight wire
• J: balance points for tilting wire
• K,L: adjustment posts for leveling apparatus
• M: mirror for detecting small changes in tilt angle
• N: magnetic brake to dampen oscillations of tilting arm
• T: tray for adding mass to upper tilting wire

Setup Instructions

1. Adjust upper arm of apparatus so that middle section of tilting wire (G) is directly above and parallel to lower wire (H).
2. Connect wires from A and D to positive and ground (respectively) of step-down transformer.
3. Connect B to C using hook-up wire.
4. Aim laser beam at mirror (M) so that reflected beam falls on a wall or flat surface and small deviations in tilt of U-shaped wire can be detected.
5. Plug step-down transformer into output of variable autotransformer (variac). Turn on variac and adjust to increase current in wires G, H.