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.

Question

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.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.

Answer 1

The correct answer is 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. When the negatively charged rod touches the foam cup, electrons will be transferred from the rod to the cup, causing a buildup of negative charge in the localized area where the rod was placed. The aluminum can, being a conductor, will not accumulate charge and will not be affected by the transfer of electrons.