Electricity and Charges

A student rubs a certain rod with plastic wrap. The rod then repels a glass rod that has been rubbed with silk and attracts a rubber rod that has been rubbed with fur. This observation shows that the first rod has a(n) _______________ charge.

• positive

• negative

• neutral

• undetermined

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Objects become electrically charged as a result of the transfer of__________________

• protons.

• electrons.

• neutrons.

• nuclei.

The nucleus of an atom has _______________ electric charge.

• positive

• negative

• neutral

• both positive or negative

Rubbing a balloon through dry hair gives the balloon a _______________ electric charge.

• positive

• negative

• neutral

• balanced

Tags

NGSS.MS-PS2-3

Robert Milliken’s research showed that electric charge is quantized, which means that

• a proton has a charge equal to that of two electrons.

• an electron can have any amount of electric charge.

• all charge is an integer multiple of a fundamental charge.

• all charge is an integer multiple of the charge of a neutron.

A negatively charged rod is brought near a metal sphere that is not grounded. When the rod is taken away, the metal sphere will have _______________________.

• positive charge.

• a negative charge.

• an induced charge.

• no charge.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Uncharged objects can be attracted by a charged object because the uncharged objects acquire a surface charge by the process of __________________.

• contact

• polarization

• conduction

• charge transfer

Tags

NGSS.HS-PS2-4

A conductor, such as a copper rod, can be charged by contact with another charged object only if the metal rod is ______________________.

• an insulator.

• grounded to Earth.

• insulated from Earth.

• positively charged.

What is the effect of one negatively charged object and one positively charged object coming close to each other.

• The objects repel each other.

• The objects attract each other.

Tags

NGSS.MS-PS2-3

What is the effect of two negatively charged objects coming near each other.

• The objects repel each other.

• The objects attract each other.

Tags

NGSS.MS-PS2-3