A solar cell generates a potential difference of 0.088 V when a 610Ω resistor is connected across it, and a potential difference of 0.12 V when a 990Ω resistor is substituted. What are the
(a) internal resistance and
(b) emf of the solar cell?
(c) The area of the cell is 1.7 cm² and the rate per unit area at which it receives energy from light is 5.7 mW/cm²? What is the efficiency of the cell for converting light energy to thermal energy in the 990Ω external resistor?