Electricty Part 2 Flashcards
What type of stored energy does a battery have?
Chemical energy that is converted to electrical energy and some of it to heat energy
What does a bulb lighting show?
Current is flowing in the circuit
What is voltage or e.m.f?
The energy used to drive one Coulomb round a complete circuit
What is resistance?
The opposition to current flow
What does resistance vary on?
Length- the longer the wire the HIGHER the resistance
Diameter-the thicker the wire the LESS the resistance
Temperature-the higher the temperature the HIGHER the resistance
Material- a good conductor has LESS resistance, a bad conductor has MORE resistance
Describe the wires in cases where a high and a small current is needed
High current needed- wires thick and short
Low current needed- wires thin and long
What is the unit of resistance?
Ohm.
What are two names of variable resistors?
Potentiometers and rheostats
When the resistors are in series to calculate the it’s resistance we….
Add the resistors
When the circuit in series the voltage across each resistors is found …..
By using the equation V=IxR
When the circuit is in series the current in the circuit is found….
By using the formula I=supply voltage:total resistance
What is the Volta meter?
A instrument used to measure voltage.
What is a multimeter?
An instrument used to measure voltage,resistance and current.
What is a galvanometer?
An instrument used to measure current flowing in two opposite directions.
What is the formula for resistance in a device connected in parallel.
RT= (R1xR2) : (R1+R2)
