Electrical Circuits Flashcards
What is Kirchoff’s Second Law?
The sum of the EMF = The sum of the potential difference in a closed loop.
In the circuit symbol for a cell, which is the positive terminal?
The longer one.
What is one volt?
The p.d across a component when 1J of energy is transferred by 1C of charge.
What is potential difference?
The work done by charges moving through a circuit component.
What is e.m.f?
The work done on charges to move them around a circuit.
What is Kirchoff’s First Law?
The sum of the currents into a circuit junction = the sum of the currents out.
In series, what is the total resistance of a set of resistors?
The resistance of each resistor added together.
In parallel, what is the total resistance of a set of resistors?
The reciprocal of the reciprocals of each resistance added together.
What are the 4 key circuit equations for analysing circuits?
I=Q/t, V=W/Q, P=IV and V=IR
What is the cause of internal resistance in a cell?
Work has to be done by the charges to move them through the cell. This energy is transferred to heat and so some potential difference is lost.
What is the terminal potential difference of a cell?
The p.d measured across the terminals of the cell that is lower than the e.m.f of the cell due to internal resistance.
In the potential divider equation, what is V-out?
The potential difference across the varying resistor.
In the potential divider equation, what is R2?
The resistance of the varying resistor.
