Other things to remember Flashcards
How is potential difference divided in series and parallel circuits?
Series Circuit:
- Potential difference is shared (divided) across all components
Parallel Circuit:
- Potential difference is the same across all components
What is the equation linking p.d. charge and energy transferred?
p.d. = energy transferred / charge
Define the volt
One volt of charge is 1 joule per coulomb of charge
In a parallel circuit what is the rule for any complete loop in the circuit?
Sum of the emfs = sum of the pds
What is ‘work’
When energy is transferred from one store to another we say that work has been done to the object
What is EMF
Electromotive force is the amount of work the battery does on (energy transferred to) each coulomb of charge
What is internal resistance?
Internal resistance is the resistance of a power supply
what are ‘lost volts’
Lost volts is the energy wasted per coulomb overcoming internal resistance (emf = p.d. + lost volts)
Define the ohm?
One ohm is the resistance an object has when it has a p.d. of 1V across it and a current of 1 amp flowing through it
What is ohm’s law?
Provided temperature is constant, the current through an ohmic conductor is directly proportional to the p.d. across it
What 3 things does the resistance of a wire depend on?
- It’s length
- It’s width
- What it’s made of
What is resistivity measured in?
Ohm metres
Calculation for raw uncertainty
Raw uncertainty = range / 2
What is power?
power is the rate of energy transfer by each electrical component.
What is the equation for power?
P = V * I
or
P = W / t (energy transferred / time)
