Examkin

Question

Difficulty: MediumCausal Detail Extraction

Read the following technical passage regarding solar array maintenance:

In photovoltaic (PV) solar array maintenance, partial shading on a single cell within a series-connected module causes that cell to become reverse-biased. Because the shaded cell cannot generate current equivalent to the fully illuminated cells, it operates as a resistive load and dissipates energy as localized heat. This localized thermal escalation directly degrades the surrounding polymer encapsulant, which subsequently causes protective layer delamination and allows moisture penetration. Over extended operational cycles, the concentrated thermal stress induces micro-cracking across the brittle silicon wafer, ultimately producing an open-circuit failure that disables the entire module string.

Based on the passage, match each stated cause on the left with its direct stated effect on the right.

  • Partial shading of an individual cell in a series moduleThe cell becomes reverse-biased and operates as a resistive load
  • Localized degradation of the polymer encapsulantProtective layer delamination occurs, permitting moisture penetration
  • Concentrated thermal stress over extended operational cyclesMicro-cracking develops in the silicon wafer, causing open-circuit failure

Answer

Partial shading of an individual cell pairs with the cell becoming reverse-biased and operating as a resistive load; degradation of the polymer encapsulant pairs with protective layer delamination and moisture penetration; concentrated thermal stress over extended cycles pairs with micro-cracking in the silicon wafer and open-circuit failure.
Each cause is paired directly with the explicit consequence stated in the text: partial shading causes reverse-biasing and resistive loading; polymer encapsulant degradation directly leads to delamination and moisture ingress; and prolonged thermal stress causes wafer micro-cracking and string failure.

Step-by-Step Solution

1
Locate the explicit cause 'partial shading' in the first sentence of the passage.
Identify the immediate consequence: the cell becomes reverse-biased and behaves as a resistive load dissipating heat.
Direct retrieval of the initial electrical cause-and-effect relationship stated in the text.
2
Trace the consequence of encapsulant degradation described in the third sentence.
Identify the direct effect: protective layer delamination and moisture penetration.
The text uses the causal signal 'which subsequently causes' to connect encapsulant breakdown to delamination and moisture ingress.
3
Examine the final sentence detailing the effects of extended thermal stress.
Match long-term thermal stress with micro-cracking and total open-circuit string failure.
The passage explicitly notes that thermal stress over time 'induces micro-cracking' and produces 'open-circuit failure'.

Key Concept

Explicit Causal Detail Extraction in Technical Passages
Estimated Time:1m 15s
Rate this question

Topics

Causal Detail Extraction

More questions from this topic