Electrostatics

+/-/neutral? A formerly neutral object that just lost some electrons.

+

+/-/neutral? An object possesses more protons than electrons.

+

+/-/neutral? An object which attracts neutral paper bits and attracts a negatively-charged balloon.

+

A rubber rod has a greater electron affinity than animal fur. The rubber rod is charged by friction with animal fur. The rubber rod is then used to charge Object A by the method of induction.

+

A rubber rod has a greater electron affinity than animal fur. The rubber rod is then used to charge an aluminum pop can by the process of induction. The pop can is then contacted to object A.

+

An object around which the electric field vector is directed outwards.

+

An object which repels a balloon (balloon E) which is repelled by a positively-charged balloon (balloon F).

+

Object A is charged by friction using animal fur. Animal fur has a greater electron affinity than object A.

+

Object A is used to charge an aluminum plate by the method of induction. The aluminum plate acquires a negative charge.

+

+/-/neutral? An object which attracts a balloon (balloon C) which is repelled by a negatively-charged balloon (balloon D).

+ and neutral

+/-/neutral? An object which attracts a negatively-charged balloon.

+ and neutral

+/-/neutral? An object possesses more neutrons than electrons.

+,-, and neutral

+/-/neutral? An object which attracts a charged balloon (balloon A) which is attracted to a negatively-charged balloon (balloon B).

+,-, and neutral

+/-/neutral? A formerly neutral object that just gained some electrons.

-

+/-/neutral? An object which attracts neutral attracts paper bits and repels a negatively-charged balloon.

-

A rubber rod has a greater electron affinity than animal fur. The rubber rod is charged by friction with animal fur. The rubber rod is then used to charge Object A by method of contact.

-

An object around which the electric field vector is directed inwards.

-

Object A is charged by contact using a negatively charged object.

-

Object A is charged by induction using a positively charged object.

-

Object A is used to charge an aluminum plate by the method of induction. The aluminum plate requires a positive charge.

-

Two initially uncharged metal spheres are in contact with each other and resting on insulating posts as shown below. A negatively charged balloon is brought near, and while it held near by, sphere B is moved to the right by sliding the base sideways. The balloon is then removed. What charge do A and B have after separation?

A: positive B: negative

This time globe X is brought near, but does not touch globe Y. While globe X is held near, a finger is touched to the far side of globe Y. The finger is then taken away, and then globe X is pulled back. What is the method of charging called? What steps are involved?

Induction 1. induce charge in neutral object (electrons shift towards positive sphere) 2. ground neutral sphere while positive sphere is close

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: During the charging process, some electrons left the electroscope and entered the glass rod.

T

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope and the glass rod now have the same type of charge.

T

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope is now charged positively.

T

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The number of electrons present in the electroscope and entered the glass rod.

T

The positively charged metal globe X on the end of the insulating handle is brought over and touched to neutral globe Y, another metal globe on an insulated post. What is this method of charging called?

conduction

A negatively-charged balloon is brought near to (without touching) a neutral electroscope. With the negatively-charged balloon held near, the electroscope is momentarily touched by a hand (ground). The balloon is then removed and the needle deflects, thus showing a charge. T/F: The charge on the electroscope is the same type of the charge on the balloon.

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: As a material, plastic has a greater affinity for electrons than cotton.

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It could exert either a repulsive or attractive influence upon neutral paper bits.

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It gained protons during the charging process.

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It lost all of its electrons to the cotton during the charging process.

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It lost negative electrons and gained positive electrons during the charging process.

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It lost neutrons during the charging process (or at the very least, its neutrons became ineffective)

f

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It would now be repelled by the piece of cotton which was used to charge it.

f

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope gained electrons during the charging process.

f

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope gained protons during the charging process.

f

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope lost all of its electrons during the charging process.

f

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope was charged by the method of induction.

f

T/F about static charges? Like charges attract.

false

T/F about static charges? A negatively charged object has lost protons.

false

T/F about static charges? A positively charged object has gained protons.

false

T/F about static charges? Opposite charges repel.

false

The balloon has rubbed on Sue D. Nym's head and then hung from the ceiling. A negatively charged rod is brought close to the balloon and the rod repels the balloon. What is this method of charging called?

friction

Two initially uncharged metal spheres are in contact with each other and resting on insulating posts as shown below. A negatively charged balloon is brought near, and while it held near by, sphere B is moved to the right by sliding the base sideways. The balloon is then removed. By what method were the spheres charged?

induction

The balloon has rubbed on Sue D. Nym's head and then hung from the ceiling. A negatively charged rod is brought close to the balloon and the rod repels the balloon. Explain how Sue's hair gained a positive charge.

it lost electrons; the electrons were transferred to the balloon

The balloon has rubbed on Sue D. Nym's head and then hung from the ceiling. A negatively charged rod is brought close to the balloon and the rod repels the balloon. How do you know this method of charging is induction?

like charges repel each other, so the balloon and rod have to both be negative

The balloon has rubbed on Sue D. Nym's head and then hung from the ceiling. A negatively charged rod is brought close to the balloon and the rod repels the balloon. What charge does the balloon have?

negative

+/-/neutral? An object which attracts a negatively-charged balloon and attracts a positively-charged balloon.

neutral

The balloon has rubbed on Sue D. Nym's head and then hung from the ceiling. A negatively charged rod is brought close to the balloon and the rod repels the balloon. What was the type of charge on Sue's hair immediately after the balloon was rubbed on it?

positive

A negatively-charged balloon is brought near to (without touching) a neutral electroscope. With the negatively-charged balloon held near, the electroscope is momentarily touched by a hand (ground). The balloon is then removed and the needle deflects, thus showing a charge. T/F: The electroscope has more protons than electrons.

t

A negatively-charged balloon is brought near to (without touching) a neutral electroscope. With the negatively-charged balloon held near, the electroscope is momentarily touched by a hand (ground). The balloon is then removed and the needle deflects, thus showing a charge. T/F: The electroscope was charged by the method of induction.

t

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It could be used to charge an electroscope negatively by the process of induction.

t

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It has an excess of protons compared to the number of electrons.

t

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It has the opposite charge as the cotton.

t

A neutral plastic strip is rubbed with cotton and acquires a positive charge. T/F: It lost some electrons to the cotton during the charging process.

t

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope needle will deflect even more if the glass rod is brought near it again.

t

A positively-charged glass rod is touched to the plate of a neutral electroscope. Upon contact, the electroscope becomes charged and the needle deflects (or leaves separate). T/F: The electroscope needle would slowly approach the neutral position if a negatively-charged balloon is brought near.

t

T/F about static charges? Like charges repel.

true

T/F about static charges? A negatively charged object has gained electrons.

true

T/F about static charges? A positively charged object has lost electrons.

true

T/F about static charges? Opposite charges attract.

true