Entry Exam Category: High School Equivalency Exams
Course: General Education Development (GED)
Exam: GED Science and Practice Test
Practice Question
Extract
Solar panels capture sunlight and convert it to electricity, using photovoltaic (PV) cells. Each PV cell has several components, including two layers of silicon. One of these layers is injected with phosphorus, which creates an excess of electrons in the layer compared to pure silicon. The other layer is injected with boron, which causes the layer to have fewer electrons than pure silicon. When the two different silicon layers are put together, electrons move from the phosphorus-injected layer to the boron- Injected layer. This gives the boron-injected layer a negative charge where the two layers meet, creating an electric field at the junction of the layers. As sunlight hits a PV cell, electrons in each silicon layer become excited and move around the layer. When any electron reaches the junction between the two layers, the electric field pushes the electron toward metal conductor strips on the outside of the cell, generating electricity.
A diagram of a PV cell being exposed to sunlight is shown below. Click on the labels you want to select and drag them into the boxes to show the components of the PV cell.
Answer Choices
- A: Phosphorus-injected layer
- B: Boron-injected layer
- C: Electric field
- D: Energy
Correct Answer: A,B,C
Rationale: The components listed (A, B, C) are key parts of a PV cell as described.