Exploring Electricity and Magnetism

Mary and Mike are working on a simple electrical project. They have a circuit consisting of a battery, a switch, and a light bulb. When Mary closes the switch, the light bulb lights up. Explain why the light bulb lights up when the switch is closed.

• The switch allows the battery to charge the light bulb directly.

• Closing the switch completes the circuit, allowing current to flow through the light bulb.

• The switch generates electricity that powers the light bulb.

• The switch increases the voltage of the battery.

Mary measures the current flowing through a resistor as 2 A and the voltage across it as 10 V. Using Ohm's Law, calculate the resistance of the resistor.

Describe how rubbing a balloon on your hair can cause the balloon to stick to a wall. Use the concept of static electricity in your explanation.

• Rubbing the balloon creates a magnetic field that attracts the wall.

• Rubbing the balloon transfers electrons from your hair to the balloon, giving it a negative charge that attracts the neutral wall.

• The balloon becomes positively charged and repels the wall.

• The friction from rubbing creates heat that makes the balloon sticky.

A coil of wire is moved through a magnetic field, and a voltage is induced in the coil. Explain how Faraday's Law of Electromagnetic Induction applies to this situation.

• The movement of the coil generates a magnetic field that cancels the original field.

• Faraday's Law states that a change in magnetic field within a closed loop induces an electromotive force (EMF) in the wire.

• The coil's movement creates static electricity that induces voltage.

• The magnetic field directly powers the coil without inducing voltage.

• 3 A

• 48 A

• 0.33 A

• 8 A

Mike and Mary are playing with a balloon. They notice that when they rub the balloon on their hair and bring it close to small pieces of paper, the paper gets picked up by the balloon. Explain why this happens using the concept of static electricity.

• The balloon's charge creates a magnetic field that attracts the paper.

• The charged balloon induces a charge in the paper, causing an attraction between opposite charges.

• The balloon's charge heats the air, causing the paper to rise.

• The balloon's charge makes the paper sticky.

Tags

NGSS.MS-PS2-3

• 27 W

• 3 W

• 81 W

• 9 W

Mary and Mike are learning about transformers in their physics class. Their teacher explains how Faraday's Law of Electromagnetic Induction is used in the operation of a transformer. Can you describe how this law is applied in a transformer?

• A transformer uses Faraday's Law to convert electrical energy into mechanical energy.

• A transformer uses Faraday's Law to change the voltage level by inducing a current in a secondary coil through a changing magnetic field.

• A transformer uses Faraday's Law to store electrical energy in a magnetic field.

• A transformer uses Faraday's Law to create static electricity.

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

• 12 V

• 3 V

• 0.33 V

• 8 V

Mike and Mary were walking on a carpeted floor. When Mike reached out to touch a metal doorknob, he felt a small spark. Explain how static electricity caused this spark.

• Walking on the carpet generates a magnetic field that causes a spark.

• Walking on the carpet transfers electrons to your body, and touching the doorknob allows the excess electrons to discharge, creating a spark.

• The carpet's friction heats the air, causing a spark.

• The doorknob generates electricity that causes a spark.