Solar Cell
Solar Cell
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US $9.75
A solar cell generates a potential difference?
1. A solar cell generates a potential difference of 0.0941 V when a resistance of 500 Ω connects through it, and a potential difference of 0.1455 V when a 1000 Ω resistance is replaced. What is the internal cell resistance solar? 2.What is the emf of the solar cell? 3. The cell area is 5.0 cm2, and the rate per unit area that receives the light energy is 2.0m W / cm2. What is the efficiency of the cell to convert light energy into thermal energy at 1000 Ω external resistance?
Here's a way to configure it. Suppose that the cell has a constant voltage source V in it, with a series resistance R. The R represents the internal resistance. If outline the first situation, see the current through the resistance of 500 ohms, by Ohm's law is 0.0941/500. This is the same current as V / (R 500), so V / (R 500) = 0.0941/500 or V = (0.0941/500) (R 500) can derive a similar equation for the 1000-ohm resistance, and since in both cases, V is supposed to be the same, you can set the two equations equal and solving for R, the internal resistance. Once you have that, you can plug back into any equation to obtain V, the open circuit emf. (Incidentally, this is a very real role model of how the crystalline silicon solar cells. But I digress.) For the third problem, remember that the power dissipated by a resistor * Power voltage (VI) or I ^ 2 * R, or V ^ 2 / R. Everyone gives the same answer.