Electromagnetics

What is the function of a switch in an electrical circuit?

• It interrupts the flow of electrons when it is closed.

• It resists the flow of electrons when it is closed.

• It resists the flow of electrons when it is open.

• It interrupts the flow of electrons when it is open.

How does increasing the length of a wire affect a circuit?

• It decreases the resistance.

• It increases the voltage.

• It increases the resistance.

• It decreases the voltage.

If the resistance of the four wires is ranked from highest to lowest, how does the resistance of a wire used to power clothes dryers rank?

• Second

• Third

• Fourth

• First

Tags

NGSS.MS-ETS1-1

The voltage between two points in a circuit is 4.2 V. If the resistance between the points is 72 Ω, what is the current, according to Ohm's law?

• 0.058 A

• 302 A

• 17.1 A

• 76.2 A

What is the formula for electrical power?

• P = I/V

• P = IR

• P = IV/R

• P = IV

Which circuit would have the most electrical power?

• I = 3.5 A, V = 0.08 V

• I = 3.1 A, V = 0.10 V

• I = 2.7 A, V = 0.18 V

• I = 4.6 A, V = 0.06 V

Which circuit would have the most electrical power?

• A. (Diagram: I = 2.2 A, V = 0.19 V)

• B. (Diagram: I = 2.0 A, V = 0.17 V)

• C. (Diagram: I = 1.6 A, V = 0.25 V)

• D. (Diagram: I = 1.2 A, V = 0.14 V)

Tags

NGSS.MS-PS2-3

Which situation results in the most attraction between two magnets?

• The north pole of one magnet is near the south pole of the other magnet.

• The south pole of one magnet is near the south pole of the other magnet.

• The north pole of one magnet is far away from the south pole of the other magnet.

• The north pole of one magnet is far away from the north pole of the other magnet.

Tags

NGSS.3-PS2-3

Which situation results in the least attraction between two magnets?

• The south pole of one magnet is near the south pole of the other magnet.

• The north pole of one magnet is far away from the north pole of the other magnet.

• The north pole of one magnet is far away from the south pole of the other magnet.

• The north pole of one magnet is near the south pole of the other magnet.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

At what location in this diagram do the magnetic field lines show that the magnetic field is strongest?

• D

• C

• B

• A

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5