Electricity Unit Review

How can an object become positively charged?

• gain electrons

• gain protons

• lose electrons

• lose protons

Kamal walked across a carpet on a dry winter day. The results are illustrated in this drawing. What happened to Kamal’s shoes and the carpet?

• Both the shoes and the carpet lost electrons.

• The shoes gained electrons and the carpet lost electrons.

• Both the shoes and the carpet gained electrons.

• The shoes lost electrons and the carpet gained electrons.

Which of the following statements about the ‘Law of Charges” is not true?

• All matter is neutral.

• Unlike charges attract.

• Charged objects attract neutral objects.

• Like charges repel.

If the two charges represented in the figure were brought near each other, they would

• attract each other

• repel each other

• cause static discharge

• have no effect on each other

In science class, your teacher rubs a glass rod with a piece of rabbit fur and moves the glass rod toward a suspended piece of vinyl. The piece of vinyl moves toward the glass rod. The reason this happens is…

• the glass rod and the piece of vinyl have opposite charges

• the glass rod and the piece of vinyl have like charges

• the glass rod and the piece of vinyl have a combined neutral charge

• the glass rod has become charged, which attracts the neutral vinyl

Charge separation occurs when…

• charged objects are brought near neutral objects

• neutral objects gain static charges from charged objects

• objects with like charges are brought close to one another

• objects with opposite charges are brought close to one another

Sandra, being quite tired and still sluggish with sleep, drags her feet across the carpet as she walks toward the bathroom. When she touches the metal doorknob, she receives an electric shock. Why?

• She has generated in the door an excess of charges and the charges are released when she touches the doorknob.

• She has generated in her body an excess of charges, which are then transferred to the doorknob when she touches it since metal is a good insulator.

• She has generated in her body an excess of charges, which are then transferred to the metal doorknob when she touches it since metal is a good conductor.

• She has generated in the door an excess of charges and the charges are released when she touches the doorknob since she is a good insulator.

The type of energy that Sandra has just experienced is called _______________ _______________.

• current electricity

• static electricity

• unbalanced electricity

• friction energy

Later in the morning, Sandra is getting dressed. She notices that when she pulls her sweater over her head, she sees little sparks between her sweater and her t-shirt. What are the sparks?

• They are atoms moving from her sweater to her t-shirt.

• They are protons that are moving between her sweater and her t-shirt.

• They are electrons that are moving between her sweater and her t-shirt.

• They are neutrons that are moving between her t-shirt and her sweater.

Sandra knows that the small sparks are nothing to be concerned about since they are just small transfers of electrical energy called electrical _______________.

• discharge

• charge separation

• polarization

• current