When do you use photovoltaics?
A. If you use your cell-phone
B. If you use a solar-powered watch or calculator
C. If you use a solar-panel
D. Both B and C
E. All of the above
Answer: D
When do you use photovoltaics?
A. If you use your cell-phone
B. If you use a solar-powered watch or calculator
C. If you use a solar-panel
D. Both B and C
E. All of the above
Answer: D