Domain: Engineering — Electrical Engineering
Target concept: Rotate a rotary potentiometer to smoothly adjust the brightness of the lamp.

Video generation prompt: On the desk, a rotary potentiometer is connected in series with a small incandescent lamp; a hand slowly rotates the knob back and forth.

Evaluation guide:
(i) Target concept: Variable resistance controls current in a series DC circuit, thereby modulating power dissipation and luminance in an incandescent lamp.
Minimum mechanism: Potentiometer must be wired in series (not parallel) with lamp; resistance must vary monotonically with rotation angle; lamp must respond to instantaneous current with thermal inertia-based brightness (no instant on/off); human hand must drive reversible mechanical input.
(ii)Storyline: [Frame 0–2] Static shot: potentiometer and lamp co-located on desk, visibly wired in series, lamp initially dim, knob at mid-position, hand resting near knob. → [Frame 3–6] Hand grasps knob and rotates it steadily in one direction; lamp brightness increases continuously and synchronously; filament glow strengthens. → [Frame 7–9] Hand reverses rotation direction smoothly; lamp brightness decreases continuously and synchronously; filament glow weakens. → Perspective: fixed frontal desk-level view, no camera motion, full visibility of knob, hand, lamp, and wire connections; no occlusion of critical elements at any time.

Manual:
Experimental Procedure
1. Place rotary potentiometer and small incandescent lamp side-by-side on a desk.
2. Connect them in series using insulated wires.
3. With hand, slowly rotate potentiometer knob back and forth.
Observation of Experimental Phenomena
Lamp brightness changes continuously: increases during one rotational direction, decreases during the opposite; warm-yellow incandescent glow intensifies and dims visibly; filament becomes brighter and more defined when bright, dimmer and less distinct when dim.
Summary of Experimental Principles
Rotating a rotary potentiometer to smoothly adjust the brightness of the lamp.

Prompt Grounding rubric:
level_1: No rotary potentiometer, no incandescent lamp, and no hand are visible in the frame together or separately; the desk surface may or may not appear, but none of the three required physical elements (potentiometer, lamp, hand) are shown.
level_2: Only one of the required elements is visible (for example the lamp alone, or the potentiometer alone, or a hand with no potentiometer in sight), or the potentiometer and lamp are both visible but no wire visibly connects them, or the wires connect them in a way that is clearly a parallel branch rather than one loop; the knob shows no rotation and no hand ever touches it.
level_3: The potentiometer, the small incandescent lamp, a hand, and the desk surface are all visible together; two wires visibly run from the potentiometer's terminals to the lamp socket, forming one series loop; the hand grips the knob and turns it, but the turning happens in only one direction for the whole clip, with no reversal back the other way.
level_4: Everything described at the 3-point level is present, and in addition the hand turns the knob clockwise for a stretch and then counterclockwise for a stretch (at least one clear reversal of direction), the hand keeps continuous contact with the knob throughout the motion, and the two wires stay visibly attached to both the potentiometer and the lamp socket for the entire clip, with no wire ever shown cut, floating, or detached.
level_5: Everything described at the 4-point level is present, and in addition the camera framing keeps the potentiometer body, the knob, the hand, both wires, and the lamp bulb simultaneously in view for the whole clip: the hand's grip never blocks the knob's rotation from view, and the wire path from potentiometer to lamp stays an unambiguous single series connection, never bundled or routed in a way that could be mistaken for a parallel branch, at every point during the back-and-forth motion.

Scientific and Causal Correctness rubric:
level_1: The lamp stays at one constant brightness (fully off, fully on, or a fixed middle level) for the whole clip no matter how the knob is turned, or the knob never actually rotates, or the bulb glows with a cool white or blue-white color rather than the warm orange-yellow expected of a heated tungsten filament.
level_2: Lamp brightness does change, but in the wrong direction relative to the knob (for example it grows brighter while the knob turns clockwise and then grows brighter again once the knob reverses to counterclockwise); or the lamp switches abruptly between a bright and a dim state instead of sliding smoothly between them, or the glow color is inconsistent with a heated filament (pure white, cyan, or greenish).
level_3: Brightness rises and falls smoothly and in the correct direction relative to the knob's rotation (turning one way brightens the filament, turning the other way dims it), and the glow keeps a warm yellow-orange incandescent color throughout; but the brightness change visibly starts before the hand begins turning the knob, or keeps changing for a moment after the hand and knob have already stopped moving.
level_4: Brightness rises and falls smoothly, monotonically, and in the correct direction as the knob turns, the glow stays warm yellow-orange with the filament visibly hotter-looking when bright and cooler-looking when dim, and the brightness change starts and stops in step with the knob's motion; but across the full back-and-forth cycle the lamp is only ever seen brightening (or only ever dimming), so the reverse trend during the return rotation is never actually shown.
level_5: The lamp's brightness rises when the knob turns one way and falls when it turns the other way, tracking the knob's motion with no noticeable delay before it starts responding and no continued brightening or dimming after the knob stops; the glow keeps a stable warm-yellow incandescent color, showing a clearly bright filament at high brightness and a dim but still glowing filament (not a fully dark bulb) at low brightness, with no flicker, flash, or sudden jump at any point.

Spatiotemporal Consistency rubric:
level_1: The potentiometer, lamp, or hand vanishes or instantly relocates between frames; the lamp bulb disappears from its socket and later reappears; the desk or wall behind the setup flexes, bends, or warps; or the motion stutters with several large, visible skips in hand or knob position rather than flowing continuously.
level_2: One clear spatiotemporal problem is visible: for example the hand's grip briefly separates from the knob while the knob keeps turning on its own, or the knob's rotation axis shifts sideways instead of staying fixed in place, or the lamp's brightness jumps sharply while the hand and knob are both completely still, or the light in the scene appears to change source or intensity within a single moment with no gradual transition, casting a shadow that switches to a noticeably different length or angle in one step.
level_3: A small, easy-to-miss flaw is present: for example the hand's motion hitches slightly right at the moment the rotation direction reverses, the lamp's brightness holds briefly steady or changes unevenly for an instant during that same reversal, or the shadow cast by the hand falls at a marginally different angle than it did a moment before with nothing in the scene to explain the change; but there is no vanishing part, no instant relocation, and no break in the wiring.
level_4: Hand motion is smooth and anatomically natural throughout, the knob turns around one fixed axis without wobbling or slipping in the hand's grip, the lamp brightness slides between levels with no visible stepped jumps or flicker, and the shadows cast by the hand and the lamp fall in the same direction and at roughly the same length as earlier in the clip, with at most one barely noticeable slip, such as a single instant where a wire's rendered thickness looks slightly off.
level_5: Hand motion is completely fluid and natural, the knob rotates smoothly about a single fixed axis with no wobble or slippage at any point, the lamp's brightness eases continuously between levels with no lag, no overshoot, and no flicker, the shadows cast by the hand and the lamp keep the same direction and length from start to finish, and the potentiometer, wires, and lamp bulb all keep their shape, size, and position on the desk relative to one another with no interpenetration or occlusion errors throughout.