OCR Gateway P6 Revision

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• Created by: charlotte
• Created on: 17-06-13 13:00
what is current?
flow of charged particles
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what is voltage?
amount of energy particles have
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what is resistance?
a materials opposition to the flow of electrons
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ohms law
voltage is directly proportional to current
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light dependent resistor (LDR)..
a ldr is designed to change it's resistance depending on how much light is shone upon it, it has a very high resistance
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what are LDR's used in?
automatic sun blinds & outdoor lighting, digital clock display
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resistance in LDR's
as light increases, resistance decreases (resistance is inversely proportional to light)
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thermistors are designed to..
change their resistance depending on the temperature of surroundings
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thermistors are used in..
thermostats, fire alarms, refrigerators & light bulbs
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resistance in thermistor
as temperature drops, resistance increases
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potential dividers..
consist of a pair of resistors, they divide the voltage in a circuit. the higher the resistance the bigger the voltage drop
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what is a magnetic field?
a region here magnetic materials experience a force acting on them
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to get a bigger voltage..
increase strength of magnet, no. of turns & speed of movement
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logic gates (AND, OR, NOT, NAND & NOR)
AND- only input if both are on. OR - input if one is on. NOT - input opposite (1 = 0) NAND - opposite input to AND. NOR - opposite to OR
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Other cards in this set

Card 2

what is voltage?

Back

amount of energy particles have

Card 3

Front

what is resistance?

ohms law

Card 5

Front

light dependent resistor (LDR)..