PHYSICS - electricity

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Diagram of cell + function
A cell stores chemical energy and then converts it into electrical energy when put in a curcuit
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Diagram of battery + function
A battery is just two or more cells joined together
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Diagram + function of a) switch b) filament lamp/ bulb
a) A switch controls the flow of electricity - if the switch is open electricity cant flow. b) A bulb converts electrical energy into light and thermal energy
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Diagram and function of a) Ammeter b) Voltmeter
a) An ammeter measures the CURRENT (amount of electricity flowing) It is always connected in SERIES. b) A voltmeter measures the POTENTIAL DIFFERENCE, it is always connected in PARALLEL
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Diagram of resistor + function, extra information
A resistor makes it different for the current to flow. The longer the wire, the more resistance there is. A resistor is a ohmic conductor where the current is directly proportional to the potential difference, graph - straight line through origin
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Diagram of variable resistor + function
A variable resistor can be adjusted to control the amount of current flowing
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Diagram of diode + function
A diode is a non-ohmic conductor (not directly proportional - therefor line on graph wont be straight) - it allows the current to flow in ONE direction only
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Diagram of LDR (Light dependant resistor) + function. What happens with increase light intensity? + give an example of everyday use
An LDR is a resistor whose resistance varies with light intensity - the more light there is, the less resistance- in darkness the resistance is highest, in light resistance falls. They could be used in automatic night lights or burglar detectors
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What is the equation for charge through a circuit?
Q=IT charge flow (C)= current (A) x time (S)
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What does ohms law state?
Ohm's law states that the current through a resistor is directly proportional to the potential difference acrosst the resistor
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What is the equation for potential difference (V)?
V=IR potential difference = Current (A) x Resistance (ohms)
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Equation for resistance (ohms)
R=V/I
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Equation for current (A)
I=V/R
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In which circuit will there be greater resistance? a) series or b) parallel & WHY
a) each electron experiences more resistance in series because the resistors are on one branch of the circuit - in parallel they are more spaced out
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what are the two main factors affecting resistance?
1. if the components are in series or in parallel 2. the length of wire - longer the wire the more resistance
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what are the three different I -V characteristics that change as the potential difference (V) across it is increased?
1. an Ohmic conductor (e.g a resistor) - line is straight as they are directly proportional 2. Filament lamp - curved line through origin,- gets less steep 3. Diode - only in positive section as current moves in 1 direction only - high resistance
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Diagram of thermistor + function - the resistance of a thermoistor depends on which factor? + give example of everyday use
A thermistor is a TEMPERATURE dependant resistor. In hot conditions the resistance drops, in cool conditions the resistance increases. an example would be a car engine or an electronic thermostat
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Other cards in this set

Card 2

Front

Diagram of battery + function

Back

A battery is just two or more cells joined together

Card 3

Front

Diagram + function of a) switch b) filament lamp/ bulb

Back

Preview of the front of card 3

Card 4

Front

Diagram and function of a) Ammeter b) Voltmeter

Back

Preview of the front of card 4

Card 5

Front

Diagram of resistor + function, extra information

Back

Preview of the front of card 5
View more cards

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