### Photometer

What is photometer?
What is a Photometer? You can comprehend its procedure of working by method for a straightforward test.

The gadget utilized for measuring the power of light is known as photometer. With its help, two such wellsprings of light can be looked at, out of which the force of one is known and that of the other, obscure. Give us a chance to perceive how it is finished.
Cut a tight depression in a wooden board and settle an erect white sheet of cardboard into it.

On the off chance that you confront any trouble in cutting the furrow, you can apply some other less demanding strategy moreover. The object is that the cardboard sheet ought to stay straight and erect. There's nothing more to it. On the board, stick one pencil each with their honed closes upwards, on both the sides of the cardboard at a separation of 4 cm from the cardboard sheet.

Presently take three candles of a similar size and settle them on a table in upright position-two on one side near each other and the third at a separation of around, 60 cm from them. Put the wooden board with cardboard and pencils precisely at the center purpose of the separation between the candles.

At that point light the candles. Of the two shadows falling on the cardboard, one will be darker. Presently advance the board gradually and in reverse till it goes to the position from where both the shadows resemble the other alike. The board will be twice far from the two candles in contrast with its separation from the single flame. It is on the grounds that the light of one flame will be half contrasted and that of the two candles.

At the point when this board is at equivalent separation from the wellsprings of light and the shadows falling on the cardboard are additionally comparable, then esteem it that the candles are giving light of equivalent power. Presently in the event that you need to know the 'flame power' of a globule, avoid it at all costs equivalent to that of the two candles continued the opposite side. At that point to make the shadows look similarly dim, continue expanding the quantity of the candles. The minute the shadows appear to be comparable, tally the quantity of the candles and this will let you know the 'flame power' of the knob.