Which of the following statements is true about a basic electrical circuit? No electricity will flow through a circuit without a light.

Electricity will flow through a circuit without a source of energy.

No electricity will flow through a circuit that has an open switch.

Electricity will flow through a circuit that forms an incomplete loop.

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters