Technologies Electricity & Magnetism

Angelina is learning how to build circuits. She starts by connecting a light bulb to a battery with copper wires. In her studies, she reads that the current flows due to a difference in potential energy in the system. Which statement describes what is happening to cause current to flow?

• Voltage is when current flows from lower to higher potential energy.
• Voltage is when current flows from higher to lower potential energy.
• Amperes is when current flows from lower to higher potential energy.
• Amperes is when current flows from higher to lower potential energy.

Mr. Bissell creates a diagram of electric and magnetic fields to teach his students about the concepts. He includes the similarities and differences between the fields on the diagram. Which of the following statements should he add about the similarities between the two fields?

• The field lines in both magnetic and electric fields are always straight.
• Each charged particle and magnet have both a positive and negative side.
• Opposite charges and poles are always attracted to each other.
• The potential energy increases as like charges or poles get farther apart.

Static electricity occurs when charges build up on an object instead of flowing. The static charge on the object can build up in one of four ways. Which of the following is NOT one of those four ways?

• friction
• conduction
• convection
• induction

Shandra is studying Earth’s magnetic field in her science class. She learns that a giant shield around her planet protects all living things from dangerous charged particles from the sun. How does the magnetic field protect life on Earth?

• The magnetic field directs charged particles toward the poles and then past Earth.
• The magnetic field directs charged particles toward the equator and then past Earth.
• The magnetic field absorbs the charged particles coming from the sun.
• The magnetic field directs charged particles toward the poles then absorbs them.

Roman is using a bar magnet in an experiment to determine how its magnetic field lines look. He accidently drops the magnet, breaking it in two. He picks up both pieces and modifies his experiment to determine what happened to the magnet when he dropped it. Which of the following statements may Roman find to be true during his experiment? Choose the two that apply.

• Both pieces of the magnet have north and south poles.
• There is an attractive magnetic force between the two pieces where they broke.
• The broken pieces of the magnet are no longer magnetic.
• Both pieces have a magnetic field that together is stronger than the original.
• Each broken piece of the magnet retains only one pole.

Tags

NGSS.MS-PS2-5

Credit cards contain a strip on the back made up of many tiny bar magnets. When the bar magnets are arranged in a certain order, they can create a code from the resulting magnetic field. The code contains information like the account number and expiration date of the card. What can happen when the credit card accidentally comes into contact with a strong magnet?

• The magnetic field on the card is created by permanent magnets that cannot be changed by another magnet.
• The magnetic field on the card can be amplified so that the card can be read from farther away.
• The magnetic field on the card can be altered so that it will contain a different account number.
• The magnetic field on the card can be disrupted, causing it to be demagnetized or unreadable.

Vincent is listing the ways that he could increase the magnetic field of the solenoid he made. Which of the following can he add to his list?

• increasing the number of loops
• spacing the loops farther apart
• decreasing the current
• adding an insulating core

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Electromagnetic induction is the process in which electricity is produced by a magnetic field. Which of the following statements are true about electromagnetic induction? Choose all that apply.

• Mechanical energy becomes electrical energy.
• A magnetic field induces a current in a wire.
• A motor uses the principle of electromagnetic induction to create electricity.
• A coil of wire moving over a magnet will create a current.

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

Larry uses a transformer to step down an incoming voltage. The transformer has ten loops in the primary coil and six in the secondary. If the incoming voltage is 120 volts, what is the outgoing voltage?

• 720
• 200
• 72
• 240

Shandra is studying Earth’s magnetic field in her science class. She learns that Earth's magnetic field... Choose all that apply.

• ...results from its iron and nickel core.
• ...protects Erath from harmful radiation from the Sun.
• ...is strongest at the north and south pole.
• ...is related to gravity and helps hold in our atmosphere.