Unit 1&2 - Electricity Flashcards
How does static electricity work?
When an object is rubbed against another object the electrons jump from one object to the other, because of friction.
What is charge separation? Hint: Gold Leaf
When opposite charges are attracted through different materials e.g. a charged rod picking up bits of paper
What is electrical current and what is it measured in?
1) the flow of electric charge i.e. flow of electrons
2) measured in Charge(C) per time (s) = Amperes (A)
What is the equation of electric current?
Current(C/s=A) = charge(C)/time(s)
What is electric Potential and what is it measured in?
1) The energy provided by a power source to drive electrons around a circuit to do useful work. Also known as the difference in electric potential energy per unit of charge.
2) Measured in Joules(J) per Charge(C) = Voltage(V)
What is the equation of electric potential? Hint: The one that includes energy.
Voltage (J/C = V) = Energy(J)/Charge(C)
What is Power and what is it measured in?
1) The rate of which a component converts electrical energy to other forms of energy.
2) Measured in Energy(J) per second(s) = Watts(W)
What are the 2 equations for Power?
1) Power(J/s=W)=Energy(J)/time(s)
2) Power(J/s=W) = Current(A) x Voltage(V)
What is resistance and what is it measured in?
1) Resistance is a measure of the opposition to current flow in an electrical circuit
2) Measured in Ohm’s (Ω)
What is the equation of resistance?
Resistance(Ω) = Voltage(V) / Current(I)
What does it mean when something is ohmic compared to non-ohmic?
1) Ohmic: when a component has a fixed resistance (gradient is linear)
2) Non-Ohmic: when a component has a varied resistance (gradient is non-linear)
What circuit are these rules from? Hint: series or parallel. I(T)=I(1)=I(2)=I(3) V(T)=V(1)+V(2)+V(3) R(T)=R(1)+R(2)+R(3)
Series
What circuit are these rules from? Hint: series or parallel I(T)=I(1)+I(2)+I(3) V(T)=V(1)=V(2)=V(3) 1/R(T)=1/R(1)+1/R(2)+1/R(3)
Parallel
What does a fuse do and why does it do it?
A fuse breaks the circuit when the maximum current a circuit is designed to carry is exceeded. This happens to prevent it from overheating and causing a fire.
What does a RCD do?
Resident Current Device is designed to monitor the active(in) and neutral(out) wires entering a house. If there is an imbalance it will switch off the electrical supply. Imbalances in current are caused by current leakage in circuits.
