How to Calculate Candle Power of Second Lamp Based on Illumination?

Calculation of Candle Power

Candle Power (C.P) Calculation:

To calculate the candle power of the second lamp, we need to first determine the candle power of the first lamp based on the given information. The illumination just below the first lamp is 20 lux, and the distance between the lamps is 8m with a height of 6m from the ground.

According to the inverse square law, the formula for illumination (I) at a distance (d) from a point source with candle power (C.P) is:

I = (C.P / 4πd²) lux

Using the information provided, we can calculate the candle power of the first lamp as follows:

20 lux = (500 C.P / 4π(6m)²)

20 lux = (500 C.P / 452.39)

C.P = (20 lux x 452.39) / 500

C.P = 18.14

Therefore, the candle power of the second lamp should also be 18.14 C.P to achieve the same illumination just below it.