CONVERTING A SOLAR ENERGY INTO ELECTRICAL ENERGY:

ITEMS REQUIRED:

One solar cell or power transistor-One milliammeter- One cardboard box-2 pieces of insulated wire- One concave mirror

PROCEDURE:

Purchase a power transistor and remove its metal cap to make a silicon solar cell. Take one milliammeter from an electronic dealer. Glue the back of the solar cell onto a cardboard box as a support. Connect two pieces of insulated wire of the cell to the ends of the milliammeter. Shield the cell from light. Your ammeter will show zero deflection. Now allow the sunlight to fall on the cell. The pointer of the ammeter will show a small deflection. Now, use a concave mirror to reflect the sunrays onto the solar cell. The mirror focuses the sunlight onto the cell. In this case, the ammeter will show greater and greater deflection as the size of the patch of light on solar cell is reduced by moving the mirror back and forth. It indicates that the photoelectric current increases as the amount of light falling on the solar cell increases.