Video Comprehension - Understanding Electrical Grounding

How does lightning form?

• Negatively charged storm clouds cause the ground to become positively charged through induction. Lightning forms when opposite charges meet.

• Negatively charged storm clouds rub against trees causing a spark called lightning.

• A property of storm clouds is their ability to produce lightning.

• The falling rain causes lightning because of friction with air particles. Because they are oppositely charged, lightning occurs when the two charges mee.

Answer explanation

As a storm cloud gets heavier, it gets lower to the ground. The bottom of the storm cloud will have a negative charge due to friction within the cloud, but because it is now closer to the ground, it will repel the electrons from the surface of the ground causing the ground to be more positive through induction. The two oppositely charged particles will attract each other and when they meet, they discharge producing a spark we call lightning.

Tags

NGSS.MS-PS2-3

What is the unit of electric resistance?

• Ampere

• Ohm

• Volt

• Coulomb

Answer explanation

The unit of electric resistance is Ohm, so the correct answer is Ohm.

What is the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit, known as?

• Newton's law

• Ohm's law

• Coulomb's law

An electric current is

• A continuous flow of electric charge

• An irregular flow of electric charge

• Only found using insulators

• Just wires connected to a magnet

The picture is an example of an:

• Electric circuit
• Electromagnet
• Electric nail
• Electric power cell

Tags

NGSS.MS-PS2-3

What does the earth represent in an electrical circuit?

• An abstraction for complex electromagnetic processes

• A magical symbol with no real-world application

• A barrier to electrical flow

• A source of infinite energy

What happens when a wire from a battery's positive side is connected to the ground?

• It generates a magnetic field

• It creates a significant electrical current

• Nothing significant happens

• It causes an immediate ground fault

Why is voltage considered confusing?

• Because it can only be measured in AC circuits

• Because it's the difference in electrical potentials between two points

• Because it's always constant

• Because it refers to a single wire

What is a ground fault?

• A failure in the grounding system

• An overload in the electrical system

• A short circuit between a phase and the ground

• A break in the neutral wire

Why are ungrounded power systems more expensive?

• Because they require less maintenance

• Because they are more efficient

• Because they use less insulation

• Because they require more insulation