Electricity and Magnetism - SA (S8P5b+c)

Electrical wires sometimes have a plastic coating wrapped around them. How does his make the wires safer to handle?

• Plastic does not react chemically with air.

• Plastic is a good insulator.

• Plastic will melt if the wires overheat.

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?

• 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.

• 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.

• 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.

• 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.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Match the following

• charging by induction

• rubbing a balloon on hair

• charging by friction

• moving a negatively charged rod near a metal sphere; touching a grounded sphere

• charging by conduction

• touching a metal sphere with a negatively charged rod

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

What type of charging is touching a metal sphere with a positive aluminum plate?

• charging by friction

• charging by conduction

• charging by induction

The pictures show four electrically charged items. Select all of the items a glass rod would attract if it were rubbed with a silk cloth, giving it a positive charge.

• balloon 1

• balloon 2

• plastic sheet 1

• plastic sheet 2

Tags

NGSS.MS-PS2-3

The picture shows a child sliding down a plastic slide. Which statement best describes why the child's hair stands up after he slides down the slide?

• Energy was transferred from the slide to the child through induction, causing the child's hair to become charged and stand up.

• Friction caused a transfer of electrons between the slide and the child, making each of his like-charged hairs repel each other.

• Energy was transferred from the child to the slide through conduction, causing the child's hair to become charged and stand up.

• Friction caused a transfer of electrons between the slide and the child, making his like-charged hairs attract the air through induction.

Max combed his hair in the morning. The picture shows what Max observed when he put the comb next to a thin stream of water coming from the faucet. Which best explains what Max saw?

• The charged comb repelled the neutral water though induction.

• The charged comb attracted the neutral water though induction.

• The charged comb repelled the neutral water though conduction.

• The charged comb attracted the neutral water though conduction.

Tags

NGSS.MS-PS2-3

Oriana touches a positively charged metal plate to a neutral metal sphere. How does the charge of the metal sphere change?

• It has an excess of positive charge.

• It has an excess of negative charge.

• It has a positive charge inside of the sphere.

• It has a negative charge inside of the sphere.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

A student is investigating the distribution of charge in a conductor. He attaches two unopened soda cans on their sides to two foam cups with tape. He sets the soda cans with the cups onto a tabletop so that they are touching one another. Then he moves a negatively charged balloon close to the left soda can. The set up for the investigation is shown. How do the electrons move in the soda cans?

• They move to the top of both cans.

• They move to the bottom of both cans.

• They move from the right can to the left can.

• The move from the left can to the right can.

Tags

NGSS.MS-PS2-3

Ronan rubs a rubber balloon on his hair. He observes that the balloon then sticks to his hair. How did the charges on the balloon and on his hair change?

• The charge on the balloon became positive. The charge on his hair became negative.

• The charge on the balloon became negative. The charge on his hair became positive.

• The charge on the balloon became negative. The charge on his hair became negative.

• The charge on the balloon became positive. The charge on his hair became positive.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5