Domain: Engineering — Electrical Engineering
Target concept: A lamp connected in parallel to the power source, removing one lamp during operation

Video generation prompt: The power supply provides electricity to two identical light bulbs connected in parallel. Both bulbs are initially lit. With the power on, one hand unscrews and removes the bulb on the left.

Evaluation guide:
(i) Target concept: Independent current paths in parallel circuits
Minimum mechanism: Power source maintains constant voltage output; bulbs are identical ohmic loads; wiring has negligible resistance; no switch or fuse intervenes in either branch.
(ii)Storyline: [Frame 0–2] Stable wide shot: two lit bulbs side-by-side, clearly wired to shared power terminals; [Frame 3–5] Hand enters from left, grasps left bulb base; [Frame 6–8] Continuous counterclockwise rotational motion removes bulb from socket; [Frame 9] Left socket empty, right bulb still lit; all events occur in fixed frontal viewpoint with no camera repositioning or zoom.

Manual:
Experimental Procedure
1. Two identical light bulbs are wired in parallel to a visible DC power source (e.g., battery with labeled +/−).
2. Both bulbs are lit at start.
3. With power ON, a hand unscrews and fully removes the left bulb from its socket.
Observation of Experimental Phenomena
- Left bulb is physically removed and no longer in socket.
- Right bulb remains continuously lit with unchanged brightness and color.
Summary of Experimental Principles
- In a parallel circuit, each branch has independent connection to the power source.
- Removing one bulb breaks only its branch; current continues flowing through the other branch.

Prompt Grounding rubric:
level_1: No two identical light bulbs are visible; no power source is shown; no parallel wiring structure connecting the bulbs is visible; no hand appears; no bulb-removal action is depicted.
level_2: Two light bulbs are present and lit, but they are not shown wired in parallel to a common power source (e.g., the wiring is ambiguous, shows a series-only path, or is absent); a hand is present but never touches or grips either bulb; no unscrewing or removal motion takes place.
level_3: Two identical light bulbs are shown wired in parallel to a single power source (e.g., a battery or a terminal block with a shared connection point); both bulbs are lit at the start; a hand enters frame and makes contact with the left bulb; an unscrewing motion begins, but the bulb is not shown fully separated from its socket before the video ends.
level_4: All conditions for score 3 are met, AND the hand performs a single continuous unscrewing motion that fully separates the left bulb from its socket on-screen, rather than cutting away before the removal is complete; the power source and its wiring remain visibly connected and undisturbed throughout the removal; the removed left bulb is shown clearly out of the socket (held in hand or set aside) rather than merely rotated in place.
level_5: All conditions for score 4 are met, AND the hand approaches from a consistent direction and performs an unambiguous counterclockwise unscrewing motion; the removed left bulb visibly separates from the socket and either exits frame or comes to rest off-socket; the emptied left socket remains visible and undisturbed after the removal; no extraneous object or hand enters the frame near the right bulb or its wiring at any point in the sequence.

Scientific and Causal Correctness rubric:
level_1: Both bulbs go dark at the same moment the left bulb is removed; the right bulb turns off as a direct result of the left bulb's removal; either bulb changes color or brightness in a way unrelated to the circuit; there is no visible causal link between the removal action and the right bulb's subsequent state.
level_2: The right bulb turns off some time after the left bulb has already been fully removed (a delayed loss of light); the right bulb flickers on and off inconsistently after the removal; both bulbs stay identically lit in a way that hides any distinction between cause and coincidence; the observed bulb behavior contradicts how a parallel circuit should respond to removing one branch.
level_3: The right bulb stays lit without any interruption from the moment the left bulb is fully removed; the left socket is visibly empty once the bulb is out; the right bulb shows no change in brightness or color before and after the removal; the timing makes clear that the right bulb's continued illumination is a direct consequence of the parallel wiring rather than a coincidence.
level_4: All conditions for score 3 are met, AND the right bulb shows no flicker, no dimming, and no transient event (such as a spark, smoke, or flash) at the instant the left bulb is removed; the emptied left socket shows no damage, discoloration, or arcing; every change visible in the scene is consistent with each bulb having its own independent connection to the power source.
level_5: All conditions for score 4 are met, AND the right bulb's brightness and color are identical before, during, and after the left bulb's removal; the left socket stays empty and structurally undamaged; nothing in the scene (such as an unexplained shadow change or reflection change) suggests a hidden connection between the two bulbs' circuits; the removal action and the right bulb's unbroken illumination are shown within the same continuous shot with no contradictory visual cue.

Spatiotemporal Consistency rubric:
level_1: The bulbs teleport between positions; the hand appears or disappears abruptly instead of entering and exiting through the frame edge; the wiring disconnects or reconnects with no hand or tool ever touching it; a bulb's light turns fully on or off with no transition frame connecting the states; the scene shows severe warping or a sudden jump in the camera's perspective.
level_2: The hand's motion toward the left bulb is jerky or contains visible skips; the lit right bulb's brightness toggles on and off without a smooth transition; the socket's shape distorts while the hand is unscrewing the bulb; the shadow cast by the hand or the lit bulb swings to a different angle partway through the shot, with no gradual change; background objects shift position inconsistently between frames.
level_3: The hand moves smoothly toward the left bulb, keeping a consistent size and scale as it approaches; the unscrewing motion is continuous, following a natural rotational path around the bulb's axis; the right bulb's light stays steady in both position and brightness throughout; the wiring and socket show no break or structural change; the light source's direction and the shadows it casts do not shift abruptly at any point.
level_4: All conditions for score 3 are met, AND every motion (the hand's approach, its grip, the rotation, and its withdrawal) is smooth and physically plausible; the bulbs, sockets, and wiring keep consistent geometry and position relative to one another across frames; the direction and relative brightness of the ambient lighting stay fixed from the first frame to the last; no object shows sudden jitter, stretching, or reshaping between frames.
level_5: All conditions for score 4 are met, AND the hand's path is fluid and progressively occludes the left bulb as it grips it; the unscrewing rotation shows an unbroken, matching angular progression from one frame to the next; the right bulb shows no visible on/off flicker and no jump in its position; the wiring keeps the exact same curvature and connection points before, during, and after the removal; no parallax or depth mismatch appears in any frame.