Chapter 8.8 Ohm's Law Flashcards

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1
Q

What does Ohm’s Law summarize?

A

The relationship between voltage, current, and resistance

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2
Q

What is Ohm’s Law?

A

The amount of current in a circuit is directly proportional to the voltage established across the circuit, and is inversely proportional to the resistance of the circuit.

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3
Q

What the the Expression for Ohm’s Law?

A

Current = Voltage/Resistance

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4
Q

Define a Current.

A

Current is a flow of charge, pressured into motion by voltage and hampered by resistance

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5
Q

What happens when there is more resistance for a circuit?

A

The current is smaller

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6
Q

What happens if the resistance for a circuit is doubled?

A

The current is cut in half

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7
Q

What is the unit of electrical resistance?

A

Ohm

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8
Q

What circuit element regulates the current inside all electrical devices?

A

Resistors

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9
Q

What do Resistors do when current flows through them?

A

They heat up

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10
Q

What must be true for you to receive an electrical shock?

A

There must be a difference in electric potential between one part of your body and another part

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11
Q

By which path do most currents pass along?

A

The path of least resistance connecting two points

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12
Q

When will you get zapped from touching a high-voltage wire?

A

If you only touch one wire, you’ll be fine as long as you don’t touch anything else of a different electric potential.
You’ll get zapped if you touch two wires of different electric potentials. This creates a difference in electric potentials between your hands.

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13
Q

What is the source of the electrons in the current that shocks you?

A

The electrons are from your own body. In all conductors, the electrons are already there.

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14
Q

How are electrons energized.

A

Electrons are energized when a voltage difference exists across different parts of your body (or other objects)

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15
Q

What is the third round prong on electric plugs?

A

It is grounded- directly connected to the ground

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16
Q

Why do some appliances have a three pronged plug?

A

Without the third prong, if the live wire accidentally came into contact with the metal surface of the appliance, and you touch the appliance, you could receive a dangerous shock. But if the plug is three-pronged, the appliance casing is grounded via the ground wire, which ensures that the appliance casing is at zero ground potential.

17
Q

What causes electric shock: current or voltage?

A

Electric shock occurs when current is produced in the body, but the current is caused by an impressed voltage