Experimental Study On Contact Charge Due To Two Spheres Collision

It has been found long before,that particles in motion can carry charge,and in sandstorm,charged particles can have effect on electromagnetic wave.However,how particles are charged,how much quantity of charge is carried by particle and what the important environment criteria and physical parameters that influence the charge quantity are is not sure.In order to find preliminary answers to these questions,we carry experimental study on contact charge due to two spheres collision in this paper.Firstly,we design and make equipment used to measure the contact charged due to two spheres collision.This equipment contains a component in which collision happens,a charge measurement component and a component which can follow the trajectory of particle.By using this equipment,we can carry experimental measurement on the collision of two spheres which can be made in identical material or not.The resolution of this equipment is that the minimum diameter of collision sphere is 2mm and the range of collision speed is 3.13m/s-5.77m/s.In this paper,we carry the charge measurement on the collision between two spheres with the same material and different sizes and different relative speeds.And for the first time,we find in experiment that after the collision of two spheres with the same material,the bigger sphere carries positive charge and the smaller carries negative charge.The quantity of charge is proportional to the diameter ratio and relative speed of the two spheres.When the relative speed is given,the charge quantity first increase and then decrease with the increase of the diameter ratio,the maximum quantity of charge appears when the ratio locates in 0.5-0.7.When the ratio of the two sphere diameters is given,charge quantity first increase and then decrease with the increase of relative speed.By tracing the trajectory of sphere,we can calculate the collision rebound angle,and find that the charge quantity is irrelevant to the rebound angle.Relative humidity is an important factor that influences the charge quantity.When the diameter ratio and relative speed are given,the charge quantity decreases with the increase of relative humidity.