Chapter 8.8 Ohm's Law
No description yet. This curated deck is ready for daily study.
Card preview (17)
What does Ohm’s Law summarize?
The relationship between voltage, current, and resistance
What is Ohm’s Law?
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.
What the the Expression for Ohm’s Law?
Current = Voltage/Resistance
Define a Current.
Current is a flow of charge, pressured into motion by voltage and hampered by resistance
What happens when there is more resistance for a circuit?
The current is smaller
What happens if the resistance for a circuit is doubled?
The current is cut in half
What is the unit of electrical resistance?
Ohm
What circuit element regulates the current inside all electrical devices?
Resistors
What do Resistors do when current flows through them?
They heat up
What must be true for you to receive an electrical shock?
There must be a difference in electric potential between one part of your body and another part
By which path do most currents pass along?
The path of least resistance connecting two points
When will you get zapped from touching a high-voltage wire?
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.
What is the source of the electrons in the current that shocks you?
The electrons are from your own body. In all conductors, the electrons are already there.
How are electrons energized.
Electrons are energized when a voltage difference exists across different parts of your body (or other objects)
What is the third round prong on electric plugs?
It is grounded- directly connected to the ground
Why do some appliances have a three pronged plug?
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.
What causes electric shock: current or voltage?
Electric shock occurs when current is produced in the body, but the current is caused by an impressed voltage