Resistance Flashcards
What is “Electrical resistance? “
- Electrical resistance is the measure of a component’s/ wire’s opposition to current.
What is resistance measured in?
- Ohms
What happens to the current as the resistance increases in a SERIES circuit?
- Current decreases
If voltage is constant
What happens to the current as the overall resistance decreases in a SERIES circuit?
- Current increases
If voltage is constant
True or False. Electrons move easily when there is a high resistance.
- False, it is harder for the electrons to flow.
What happens to the current as potential difference in a power supply increases?
- Current increases
If temp is constant
Why does the current increase when the potential difference increases?
- Each coloumb of charge has more energy meaning it will pass a fixed point quicker in a second.
What are the 2 main points in Ohms Law?
- If voltage is constant and resistance increases, current will decrease.
- If resistance is constant and voltage increases, current will increase.
If temperature is constant
In what two main parts of the circuit is there resistance?
- Metal wires
- Metal components
What type of particle acts as a form of resistance for electrons?
- Metal ions act as a form of resistance.
Negative attracts to positive
What is the equation that links potential difference, current and resistance?
V= I x R
Voltage = current x resistance
How do you calculate the total resistance in a series circuit?
- You add the values for each resistor.
If two resistors are placed in parallel, explain what happens to the overall resistance of circuit?
- Overall resistance of circuit decreases.
Explain why resistance decreases when resistors are placed in parallel.
- More paths for electrons to take.
- Overall current increases
Electrons aren’t all in one place
Why is it useful to use a variable resistor when calculating resistance of component?
- Varies the current
- Current varies potential difference
This gives a SET of values
