A student rubs a rubber rod with fur, producing a negative charge on the rod. The student then touches the rod to a hollow, neutral metal sphere that stands on an insulating plastic stand. This transfers negative charges from the rod to the sphere:
image 63f9196b581c4f17bbe56cfd6ddd781f
Which statement best predicts what will happen to the charge, and why?
A.
It will quickly spread to the air around the sphere, because it will seek to occupy as large a volume of neutral matter as possible.
B.
It will remain at the point of contact between the rod and the sphere, because resistance in the metal prevents the charges from easily moving.
C.
It will distribute itself evenly over the surface of the sphere, because like charges repel and the sphere is a conductor.
D.
It will slowly drift to the bottom of the sphere, because the charges rapidly attach to individual atoms, making them slightly heavier than surrounding atoms.
what is the correct option?
The correct option is C. It will distribute itself evenly over the surface of the sphere because like charges repel and the sphere is a conductor. When the negatively charged rod touches the neutral metal sphere, the negative charges on the rod will repel the negative charges on the sphere. As a result, the negative charges will distribute themselves evenly over the surface of the sphere, creating an even negative charge on the sphere. Since the sphere is a conductor, the charges can move freely within it.
A student is investigating the distribution of charges in insulators. The student will place an aluminum metal can on top of a foam cup and touch the side of the foam cup with a negatively charged rod. The set up for the investigation is shown in the diagram.
What will MOST LIKELY happen to the electrons when the rod touches the foam cup?
A.
The electrons will pass to the foam cup but will remain in a localized, positively charged area on the cup where the rod was placed.
B.
The electrons will pass to the foam cup but will remain in a localized, negatively charged area on the cup where the rod was placed.
C.
The electrons will pass from the foam cup to the aluminum can, and both the foam cup and the aluminum can will become positively charged.
D.
The electrons will pass from the foam cup to the aluminum can, and both the foam cup and the aluminum can will become negatively charged.
what is the correct option?