Domain: Engineering — Instrument and Meter Engineering
Target concept: Digital Multimeter

Video generation prompt: Set the digital multimeter to the voltage range (DC 0-20V), and connect the red and black probes to the positive and negative terminals of a dry cell battery (1.5V), respectively. Measure one, two, and three dry cell batteries connected in series sequentially, with the lens aligned to the multimeter display.

Evaluation guide:
(i) Target concept: Direct-current voltage measurement of series-connected electrochemical cells using a digital multimeter.
Minimum mechanism: Dry cell batteries must maintain open-circuit voltage near 1.5V each; multimeter must be in DC voltage mode with sufficient input impedance to avoid loading; series connection requires physical +– terminal bridging; polarity-sensitive measurement yields signed voltage proportional to net EMF.
(ii)Storyline: Frame opens on multimeter with dial visibly set to DC voltage range (V–). Red probe approaches and contacts + terminal of first battery while black probe simultaneously contacts – terminal; display updates to ~1.5V and stabilizes. Then, second battery is placed adjacent to first with its – terminal touching first"s + terminal; probes are repositioned to outer + and – terminals; display updates to ~3.0V and stabilizes. Finally, third battery is added in same fashion; probes repositioned; display updates to ~4.5V and stabilizes. Throughout, lens remains fixed on multimeter display; no cut, no reframe, no occlusion of display; all battery and probe interactions occur fully in-frame with continuous visible motion; lighting and perspective remain constant.

Manual:
Experimental Procedure
1. Set digital multimeter dial to DC voltage range (V–, 0–20V).
2. Connect red probe to positive (+) terminal of one dry cell battery; black probe to negative (–) terminal.
3. Observe and record displayed voltage.
4. Add second dry cell battery in series (+ to –); reconnect probes to outer terminals.
5. Observe and record displayed voltage.
6. Add third dry cell battery in series; reconnect probes to outer terminals.
7. Observe and record displayed voltage.
Observation of Experimental Phenomena
- Multimeter display shows ~1.5V for one battery, ~3.0V for two batteries, ~4.5V for three batteries — all positive values, increasing sequentially.
- Red probe consistently contacts positively marked battery terminal; black probe contacts negatively marked terminal in all cases.
- Batteries are physically stacked end-to-end (+ to –) with visible terminal alignment.
Summary of Experimental Principles
- Digital multimeter measures potential difference in DC voltage mode.
- Dry cell batteries in series add their electromotive forces: V_total = V₁ + V₂ + V₃.
- Correct probe polarity ensures positive display reading; reversed polarity would yield negative value.

Prompt Grounding rubric:
level_1: No digital multimeter appears; no dry cell batteries appear; no red or black probe is shown touching anything; the display shows no numeric value; no one/two/three-battery sequence is attempted.
level_2: A multimeter is visible, but at least one of the following is missing or unclear: the probes, an identifiable battery, or a numeric reading on the display; whatever objects are present are never shown working together, e.g., probes lie unconnected or the display stays blank.
level_3: The multimeter is shown with red and black probes attached, at least one dry cell battery is visible, and the display shows some numeric value, but the two-battery and three-battery steps are missing, incomplete, or never shown in sequence.
level_4: The multimeter, red probe, black probe, and all three battery configurations (one, two in series, three in series) are shown; the display shows a numeric reading for each of the three measurements in order; the red probe consistently touches the positive terminal and the black probe the negative terminal at each step.
level_5: In addition to the above, the dial is clearly turned to the DC voltage setting before any measurement begins, each probe tip visibly touches its matching terminal with no visible gap, the displayed digits stay steady and readable through each of the three measurements, and the camera stays trained on the display without a cut, zoom, or reframe across all three measurements.

Scientific and Causal Correctness rubric:
level_1: The display shows something other than a voltage reading (e.g., a resistance or AC symbol, or a blank/off screen); or the same value is shown for one, two, and three batteries; or the probes are swapped (red on the negative terminal) and a negative reading appears but is never corrected.
level_2: The display shows volts, but the values make no physical sense for dry cells, e.g., 0.0 V with a battery connected, over 6 V for three batteries, or a reading that doesn't increase as batteries are added; or the probes are swapped with no negative sign appearing to reflect it.
level_3: The three displayed values increase across the sequence and are plausible for dry cells (roughly 1.5 V, 3 V, and 4.5 V); the red probe touches the positive terminal and the black probe the negative terminal throughout with no negative sign shown; however, one reading is skipped, mismatched to the battery count, or unstable while nothing about the setup itself is changing.
level_4: All three readings are positive and increase in order across one, two, and three batteries, with each step visibly larger than the last; the red probe touches the marked positive terminal and the black probe the marked negative terminal in every measurement; no reading shows a negative sign or reads zero while batteries are connected.
level_5: In addition to the above, each reading falls within about 1.2–1.6 V for one cell, 2.4–3.2 V for two cells, and 3.6–4.8 V for three cells, with no implausible jump or drop between steps, and no error indicator (such as 'OL' or a low-battery icon) appears on the display during any of the three measurements.

Spatiotemporal Consistency rubric:
level_1: The multimeter or a battery vanishes and reappears between shots; a probe jumps from one terminal to another with no motion shown in between; the display changes value with no probe touching anything and no battery added; the lighting shifts abruptly from one measurement to the next.
level_2: One clear break in continuity occurs: for example a probe is shown already touching a terminal with no approach visible, the battery stack appears fully assembled with no stacking motion shown, or the display updates before the probe visibly makes contact.
level_3: The probes approaching the terminals, the batteries being added one by one, and the display updating are all shown happening on screen with continuous motion, and nothing vanishes or jumps between shots, but one small hiccup occurs, such as a hand briefly and only once blocking the view of the display during one of the three measurements.
level_4: The red and black probe tips move continuously into contact with the terminals with no cut or jump; batteries are stacked one at a time with visible hand motion; the display updates only once contact is made and then holds steady; no shadow or lighting shift accompanies the probe or battery changes; the display never shows blurring, doubled digits, or partially missing digits.
level_5: In addition to the above, the probe tips visibly slow down as they near each terminal rather than snapping into place, each added battery sits flush against its neighbor with no visible gap, the multimeter body stays perfectly still throughout all three measurements, and the digits update promptly once contact is made, with no lag, flicker, ghosting, or dropped-digit artifact on the display.