gravity, fluid friction, and i think two more i just cant remember them
Answer:
Intensity at 45 cm will be 0.2283 volt
Explanation:
We have given that intensity of signal measured by the detector is 0.74 volt at a distance of 25 cm
We know that intensity of signal is given by
, here s is strength of light and r is distance
So 

In second case
Intensity is given by 
So 