Domain: Natural Science — Physics
Target concept: The deflection of the compass needle when the current is turned on and off nearby

Video generation prompt: A straight conductor is placed a few centimeters above a compass on the table, and is connected to a battery and a switch. The camera is fixed, and one hand alternately turns the switch on and off.

Evaluation guide:
(i) Target concept: Magnetic field generation by electric current in a straight conductor, detectable via compass needle deflection.
Minimum mechanism: Current must flow through conductor → induces circumferential magnetic field → exerts torque on compass needle’s magnetic dipole → causes reversible angular displacement proportional to field strength and inverse to distance.
(ii)Storyline: [Frame 0–t1] Static scene: compass needle aligned N–S; conductor stationary above it; switch open; hand idle near switch. [t1–t2] Hand actuates switch to closed position → conductor energized → magnetic field appears → needle begins rotating. [t2–t3] Needle settles into new stable orientation perpendicular to conductor. [t3–t4] Hand opens switch → current stops → magnetic field collapses → needle rotates back. [t4–t5] Needle fully re-stabilizes at original N–S orientation. All phases observed from fixed viewpoint with full visibility of compass face, conductor, switch, and hand–switch interaction.

Manual:
Experimental Procedure
1. Place compass flat on table. Position straight metallic conductor horizontally, centered a few centimeters directly above compass needle.
2. Connect conductor ends to battery terminals via wires, inserting a manual switch in one wire.
3. Fix camera view: top-down or slightly angled, showing compass, conductor, switch, battery, and hand.
4. With switch initially OFF, record. Then press switch ON once, hold briefly, release to OFF.
Observation of Experimental Phenomena
When switch is OFF: compass needle points steadily along Earth"s magnetic north–south axis.
When switch is ON: needle deflects ~90°, aligning perpendicular to conductor; direction depends on current flow (right-hand rule).
When switch returns OFF: needle swings back and stabilizes at original north–south orientation.
Summary of Experimental Principles
Electric current generates a circular magnetic field around a straight conductor. This field interacts with the compass magnet, causing deflection. Field direction follows right-hand rule; field strength drops rapidly with distance, so proximity is essential.

Prompt Grounding rubric:
level_1: No straight conductor is shown, no compass appears, no battery or switch is visible, and no hand action occurs; alternatively the camera view is unstable (panning, tilting, zooming, or cutting between angles), so the setup is never held in one fixed frame.
level_2: A conductor, compass, battery, switch, or hand appears on screen, but the arrangement described in the prompt is broken: for example the conductor is not held above the compass, the switch is not something the hand actually operates, the wiring linking battery, switch, and conductor is missing or disconnected, or the camera framing shifts partway through.
level_3: The compass, straight conductor, battery, switch, and a hand are all visible together; the conductor is suspended a few centimeters directly above the compass; wiring visibly links the conductor, switch, and battery into one circuit; the hand rests at or near the switch; and the camera holds one fixed framing for the entire shot, with no pan, tilt, zoom, or cut.
level_4: The compass, conductor, battery, switch, and hand remain arranged as at the 3-point level, and in addition the hand visibly toggles the switch between two clearly distinct positions (open contact and closed contact) at least once, while the conductor stays stationary directly above the compass throughout the toggle.
level_5: The arrangement and toggle described at the 4-point level hold, and further the switch sequence runs OFF, then ON, then OFF again in that order, filmed as one unbroken take with no cuts or edits. The compass, conductor, switch, and hand all stay continuously in frame from the first OFF state through the final OFF state.

Scientific and Causal Correctness rubric:
level_1: The compass needle shows no deflection at any point even though the switch is toggled ON, or the needle deflects while the switch stays OFF, or the direction the needle swings contradicts the right-hand rule for the current direction implied by the visible battery polarity and conductor orientation, or the needle keeps drifting continuously rather than settling.
level_2: The needle deflects during only one of the two switch states (for instance it swings when the switch closes but fails to swing back when the switch opens, or vice versa), or the sense of the deflection is reversed relative to what the right-hand rule predicts for the shown polarity and orientation, or the needle creeps slowly instead of responding promptly to each switch change.
level_3: The needle settles into two distinct, recognizable orientations tied to switch state: close to the compass's normal north-south heading while the switch is OFF, and rotated toward perpendicular to the conductor while the switch is ON; the sense of that ON-state rotation matches the right-hand rule given the visible battery polarity and conductor orientation.
level_4: The two orientations described at the 3-point level are clearly distinguishable from one another (not a marginal wobble), and the needle holds steady in each orientation once it arrives there, without continuing to creep or oscillate while the switch is left untouched in either state.
level_5: The distinct, steady orientations described at the 4-point level are present, and further the needle's rotation begins only once the switch visibly changes state, without a noticeable delay or an early anticipatory twitch, the needle's OFF-state heading after the ON period matches its original OFF-state heading, and no partial deflection lingers once the switch has returned OFF.

Spatiotemporal Consistency rubric:
level_1: Severe continuity breaks: the conductor, compass, or switch instantaneously appears in a different spot or vanishes between shots; the needle jumps from one angle to another without sweeping through the angles in between; the scene's lighting flips direction or brightness abruptly with no matching change in the physical setup; or visible seams or duplicated frames interrupt what should be one continuous take.
level_2: Moderate continuity breaks: the vertical gap between conductor and compass changes between the OFF and ON portions without any hand adjustment shown; the needle's rotation visibly skips across an arc instead of sweeping through it; shadows cast by the conductor, switch, or hand shift orientation in a way inconsistent with a single steady light source; or the switch's shape briefly warps between its open and closed states.
level_3: The conductor keeps the same vertical spacing above the compass for the whole shot, the hand stays adjacent to the switch without an unexplained gap opening between them, the compass housing and needle keep a rigid, unchanging shape, no piece of the setup disappears or gets swapped out mid-shot, and shadows keep a single consistent cast direction throughout.
level_4: The continuity described at the 3-point level holds, and in addition the hand's press-and-release motion at the switch reads as one smooth, anatomically plausible gesture with no missing intermediate poses, and the needle's rotation sweeps visibly through the angles between its two orientations rather than skipping, coming fully to rest before the next switch action begins.
level_5: The smooth motion described at the 4-point level holds, and further the hand maintains visible contact with (or clear proximity to) the switch throughout the entire press-and-release motion with no unexplained gap or jump in that relationship, the camera framing shows no drift suggesting hidden movement, and the conductor's spacing above the compass never noticeably shifts at any point in the take.