Question
I am sure I'm doing the last part of this question right but am not getting the right answer. Please explain.
A solar cell generates a potential difference of 0.0893 V when a 500 Ohm resistor is connected across it, and a potential difference of 0.1316 V when a 1000 Ohm resistor is substituted. What is the internal resistance of the solar cell? 9.00 Times 102 ohms What is the emf of the solar cell? 2.50 Times 10-1 V The area of the cell is 5.0 cm2, and the rate per unit area at which it receives energy from light is 2.0m W/cm2. What is the efficiency of the cell for converting light energy to thermal energy in the 1000 Ohm external resistor? (Give answer in %. Do not enter unit)
Explanation / Answer
total input= 5*2mW= 10 mW
output =(0.1316/(1000+900))^2 *1000= 4.79*10^-3 mW
efficiency= output*100/input
0.0479 %