The items listed below include some SI quantities. Underline the one that is not an SI base quantity: charge, current, length, time.
A square solar panel with side length $1300\,\text{mm}$ is shown in Fig. 1.1. Light falls normally onto the solar panel. The power of the light incident on the solar panel is $750\,\text{W}$. Calculate the intensity of the light.
The percentage uncertainty in the incident power is $\pm 3\%$. The uncertainty in each side length is $\pm 5\,\text{mm}$. Calculate the percentage uncertainty in the intensity of the light.
The useful power output of the solar panel is $160\ \text{W}$. Calculate the percentage efficiency of the solar panel.
A second square solar panel is positioned so that light of the same intensity is incident normally on it. The new panel has shorter sides than the original panel. The new panel has the same power output as the original panel. State and explain whether the efficiency of the new panel is greater than, less than or the same as the efficiency of the original panel.