New Unit 2 - Electricity Flashcards
What is the definition of current? (I)
flow of electrical charge
Measurement for current:
A - Ampere
What is the definition of potential difference? (V)
Driving force that pushes charges round.
Measurement for potential difference:
V - Volt
What is the definition of Resistance? (R)
Anything that slows down charge flows.
Measurement for resistance:
Ohm - Ω
What is a ohmic conductor?
When current is directly proportional to potential difference (at constant temperature) so resistance does not change.
What is the equation for charge? (Coulombs)
Charge (C) = Current x Time
Q = I x T
What is the equation linking potential difference, current, and resistance?
Potential difference = Current x Resistance
V = I x R
What is a variable resistor?
A resistor of which can have its resistance increased and decreased.
What is an LDR?
Light dependent resistor - Resistor of which has its resistance change depending on exposure to light. Its resistance decreases and light intensity increases.
What is a thermistor?
A resistor of which has its resistance change depending on temperature. An increase in temperature will cause a decrease to resistance.
What is an Ohmic conductor?
A conductor where current is directly proportional to potential difference. Therefore, resistance does not change.
What are examples of Ohmic conductors?
(standard) Resistors.
What are examples of Non-Ohmic conductors?
Filament lamp
Diode
LED
LDR
Thermistor
