Domain: Natural Science — Physics
Target concept: Oersted's Experiment: A straight conductor carrying current from a battery causes the compass needle to deflect.

Video generation prompt: A straight horizontal wire is placed above a compass and connected to a battery and a switch; closing the switch allows current to flow, then the switch is opened and the battery is reversed, and the procedure is repeated.

Evaluation guide:
(i) Target concept: Magnetic field generation by electric current in a straight conductor, detectable via compass needle alignment.
Minimum mechanism: Current flow must produce a circumferential magnetic field around the wire; compass needle must be free to rotate and respond to local field direction; wire must be oriented parallel to compass plane so field exerts lateral torque on needle; battery reversal must invert current direction to invert field orientation.
(ii)Storyline: Frame 1–2: Static setup (wire centered horizontally above compass, battery and switch visible and connected). Frame 3–4: First switch closure, needle begins rotating smoothly from rest to new lateral orientation. Frame 5–6: Switch opening, needle rotates smoothly back to original orientation. Frame 7–8: Battery reversal, battery rotates or flips visibly with terminals swapping positions. Frame 9–10: Second switch closure, needle rotates smoothly in opposite direction to first trial. All events occur from fixed frontal viewpoint; compass remains level and centered; wire never touches compass; no occlusion of needle tip or pivot.

Manual:
Experimental Procedure
1. Place a straight horizontal wire directly above a compass.
2. Connect wire ends to a battery and an open switch in series.
3. Close switch → observe compass needle deflection.
4. Open switch → needle returns to original orientation.
5. Reverse battery terminals.
6. Close switch again → observe reversed needle deflection.
Observation of Experimental Phenomena
The compass needle deflects laterally when current flows; deflection direction reverses when battery polarity is reversed; needle returns to initial orientation when current stops.
Summary of Experimental Principles
Oersted"s Experiment: Electric current in a straight conductor generates a circular magnetic field perpendicular to the current direction; the compass needle aligns with the net magnetic field, so reversing current reverses field direction and thus needle deflection.

Prompt Grounding rubric:
level_1: No straight wire is shown positioned above a compass, or the battery, switch, or compass itself is missing entirely: for example, only a compass and battery appear with no wire, or the demonstration shows an unrelated circuit with no compass at all.
level_2: The wire, compass, battery, and switch are all visible, but the setup contradicts the prompt: the wire is not positioned above the compass (e.g., it runs beside or below it), the battery and switch are not shown wired to the wire, the switch has no visible lever/toggle so its open or closed state cannot be judged, or the compass is tilted or turned so its needle is not visible face-on.
level_3: The straight wire is positioned above the compass, the battery and switch are wired to the wire in series, the switch is shown closing and later opening exactly once as the prompt describes, and the compass needle and dial stay clearly visible throughout this first trial.
level_4: In addition to the setup above, the battery reversal called for in the prompt is clearly shown (the battery is rotated end-for-end or its terminals are visibly swapped), after which the switch is closed a second time, so both the original trial and the reversed-battery trial are fully depicted with the same wire-battery-switch wiring intact.
level_5: In addition to the above, the wire remains directly above the same spot on the compass and the compass stays level and in the same location on the surface for the entire sequence; the battery and switch also keep the same positions relative to the wire from the first trial through the reversal and into the second trial, with no object swapped, moved, or reframed differently between the two switch closures.

Scientific and Causal Correctness rubric:
level_1: The compass needle never deflects during either switch closure, or its motion has no relationship to the switch at all (for example it starts moving before the switch closes, keeps moving after the switch opens, or drifts continuously regardless of whether the switch is open or closed), so no link between current flow and a magnetic field is demonstrated.
level_2: The needle does deflect during at least one switch closure, showing some link between current and needle motion, but the core mechanism is still wrong: the deflection is in the same direction in both trials even though the battery was reversed (i.e., no reversal of deflection is shown), or the needle only moves during the battery-flipping step itself rather than during switch closure, or the needle rotates past 180 degrees, spins continuously, or snaps between orientations instead of turning smoothly to a new resting angle.
level_3: The needle deflects visibly during the first switch closure, in a direction consistent with the current's circular field around the wire (right-hand rule) for that current direction; it returns to its original resting orientation once the switch opens; after the battery is reversed and the switch is closed again, the needle deflects a second time to the opposite side of center from the first trial.
level_4: Both trials show the deflection and reversal described above, and in addition the size of the deflection looks comparable between the two trials (neither trial shows the needle barely moving while the other swings to a large angle), each rotation is smooth and single-directional rather than wobbling back and forth, and the compass body itself never rotates, tilts, or slides when the needle moves.
level_5: In addition to the above, the needle sits still and centered right up until each switch closes, begins turning promptly once the switch closes with no perceptible delay, and stops turning and holds its new angle without drifting or overshooting once the switch opens; the reversal is unambiguous: the needle plainly ends up on the opposite side of center in the second trial compared to the first.

Spatiotemporal Consistency rubric:
level_1: At some point the wire, compass, battery, or switch vanishes from the shot, a duplicate of one of them appears elsewhere in the frame, or the shot cuts to a different lighting or framing with no transition: any break in which an object's presence or location on screen fails to persist as part of one continuous setup.
level_2: The wire, compass, battery, and switch each stay present and in a single location throughout (none of the breaks described in the 1-point case occur), but at least one required motion is shown as an instantaneous jump rather than a continuous motion: for example the needle appears already at its deflected angle with no rotation shown in between, the battery appears already reversed with no flipping motion shown, or the switch lever is open in one frame and closed in the next with no visible actuation in between.
level_3: Every required motion unfolds continuously: the needle visibly sweeps through the in-between angles as it moves to its deflected position and back, the battery visibly rotates or its terminals are visibly swapped rather than appearing pre-reversed, and the switch lever visibly moves through its throw; meanwhile the wire, compass, battery, and switch keep the same positions relative to one another throughout.
level_4: In addition to the continuous motion above, the sequence of events matches the procedure: the switch visibly closes before the needle begins turning, the needle finishes returning to rest before the battery-reversal motion begins, and the battery-reversal motion finishes before the switch closes a second time, so no motion appears to happen before the event that is supposed to trigger it.
level_5: In addition to the correct order and continuous motion above, the whole sequence plays as one smooth take with no stutter, freeze, or repeated frame anywhere; the needle's rotation about its pivot looks physically natural, turning in place rather than sliding or floating across the dial; and the camera viewpoint, framing, and scene lighting remain the same from the first switch closure through the second.