Section 21 - Electricity and circuits - Series and parallel circuits, energy and power Flashcards
What will happen if you remove or disconnect one component in a series circuit?
Circuit is broken and they all stop working
Rule for current in series circuit?
Current is same everywhere.
Rule for p.d. of supply in series circuit?
p.d. shared between components
What happens to total resistance when you add more resistors in a series circuit? Why?
Total resistance increases because the two resistors have to share the total p.d.
What will happens if you remove or disconnect one component in a series circuit?
It will hardly affect the other components at all
Rule for p.d. in parallel circuit?
p.d. is same across all components
Rule for current in parallel circuit?
Current is shared between branches. Total current flowing around circuit equal to total of all currents through separate components
Rule for current at a junction in a parallel circuit?
Total current current going into junction equal to total current leaving junction
What happens to total resistance when you add more resistors in a parallel circuit? Why?
Total resistance decreases if second resistor added in parallel because current has more than one direction and junction to go in so increased total current flowing around circuit. Increase in current means decrease in total resistance
Equation for energy transferred to an electrical component?
Energy transferred (J) = Current (A) x p.d. (V) x time (s) E = I x V x t
What do fuses do to protect circuits?
They melt and break the circuit if the current gets too high
Equation for power?
Power (W) = energy transferred (J) ÷ time (s)
P = E ÷ t
Equation for electrical power transferred by an appliance? Equation if you don’t know p.d.?
Electrical power (W) = Current (A) x p.d. (V) P = I x V Without p.d.: P = I²R
