Understanding Electricity and Electromagnetic Fields

What is the distance that the hypothetical circuit's wires would stretch to and back?

• To the moon and back

• Halfway to the moon and back

• To Mars

• Around the Earth's equator

What incorrect assumption is commonly made about electricity flow?

• It flows through water

• Electrons carry energy directly to devices

• It is always constant

• It can only travel in a vacuum

What did James Clerk Maxwell discover about light in the 1860s and 70s?

• It is made up of oscillating electric and magnetic fields

• It is a wave in the water

• It consists of particles

• It can be split into different colors

Tags

NGSS.MS-PS4-1

NGSS.MS-PS4-2

What does the Poynting vector represent?

• The flow of water in pipes

• The resistance in an electrical circuit

• The direction and magnitude of energy flow in electromagnetic fields

• The speed of light

Tags

NGSS.HS-PS4-5

What did the Poynting vector's introduction change about our understanding of energy transmission?

• Confirmed the water flow analogy

• Proved that AC is more efficient than DC

• Demonstrated the superiority of copper wires

• Showed that energy is transmitted through fields, not electrons

Tags

NGSS.HS-PS3-5

NGSS.HS-PS3-2

How does energy flow from a power plant to your home according to the video?

• By mechanical means

• Via direct current only

• Through the movement of electrons

• Through oscillating electric and magnetic fields

What was the main issue with the first Trans Atlantic cable?

• It was not waterproof

• It was too short

• Signal distortion due to increased capacitance

• Sharks bit through it

Why do most power lines today are suspended high up?

• To make maintenance easier

• To reduce the capacitance and allow for better field propagation

• For aesthetic reasons

• To avoid animals

What was the key to solving the issues with undersea telegraph cables?

• Inventing the internet

• Using thicker cables

• Understanding that fields around the wires carried energy and information

• Switching to wireless communication

Tags

NGSS.HS-PS3-5

NGSS.HS-PS4-5

NGSS.HS-PS2-5

How long would it take for the light bulb in the hypothetical circuit to light up?

• 2 seconds

• Instantaneously

• 1/c seconds

• 1 second