circuits Flashcards

16297771648	what way does the conventional current flow?	from positive to negative	0
16297792174	What way do electrons flow?	from negative to positive	1
16297823145	which components will only allow current to flow in forward bias?	LED and diode	2
16297899448	What makes metals good conductors?	They have delocalised/conduction electrons which drift slowly along the wire	3
16297916558	what is kirchoffs first law?	current and charge are always conserved	4
16297986662	how is the movement of electrons through a metal described?	random as there is no overall net movement	5
16298018756	why do electrons drift slowly through the copper lattice?	because they can only go a small distance before colliding with another atom	6
16298054018	what has to be applied across the ends of a wire to cause current to flow?	potential difference	7
16298127104	Why are insulators poor conductors?	they contain very few delocalised electrons	8
16298150949	why do semiconductors undergo doping?	because this adds impurity atoms to improve their conductivity	9
16298198076	what is the equation for EMF?	energy transferred over time	10
16298208689	what is the equation for pd?	work done over time	11
16298239922	What is Ohm's Law?	The current through an ohmic conductor (at a constant temperature) is directly proportional to the potential difference across the resistor.	12
16298321226	what factors affect electrical resistance?	the material, its length, the cross sectional area and the temperature	13
16298520095	what is resistivity affected by?	temperature	14
16298630810	how do you convert from joules to kwh?	divide by 3600000	15
16298646738	how do you convert from kwh to joules	multiply by 3600000	16
16298688704	what is this a graph for?	a filament lamp	17
16298668060	what is this a graph for?	LED	18
16298716823	what is this a graph for?	resistor	19
16298758839	what is kirchoffs second law?	The total emf around a series circuit = the sum of p.d.s across each component.	20