Circular Perspex Block for Refraction Item Type_Cell Model where current through a coil

where current through a coil closes a separate contact and shows how a small signal controls a larger circuit

Used to verify R = rho*L/A by isolating wire material

Cast-iron uprights support a 38cm expansion bar against a friction-pointer dial reading 0 to 90 degrees

Demonstrates composition and resolution of forces by attaching masses through pulleys on a force board

Used to demonstrate parallel-circuit current and brightness behavior

Circular Perspex Block for Refraction Item Type_Cell Model where current through a coilRound perspex refraction block, the curved face geometry letting beams enter along any radius for clean Snell's law angle work in ray box and refraction setups.