22.1 – Investigating Current and Voltage Relationships (Leaving Cert Physics): Flashcards
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Practise the cards
15 cards from this deck
Define ohmic conductor
Define ohmic conductor
Material where current is directly proportional to voltage at constant temperature
Ohm's Law formula
Ohm's Law formula
I and V relationship in ohmic conductors
I and V relationship in ohmic conductors
Directly proportional
Key requirement for ohmic behaviour
Key requirement for ohmic behaviour
Constant temperature
How to connect ammeter in circuit
How to connect ammeter in circuit
In series
How to connect voltmeter in circuit
How to connect voltmeter in circuit
In parallel
Shape of I vs V graph for ohmic conductor
Shape of I vs V graph for ohmic conductor
Straight line through origin
What does gradient of I-V graph equal?
What does gradient of I-V graph equal?
rac{1}{R}
Formula for resistance
Formula for resistance
R = rac{V}{I}
Calculate resistance from I-V graph gradient
Calculate resistance from I-V graph gradient
R = rac{1}{ ext{gradient}}
Main source of error in experiment
Main source of error in experiment
Heating effects from large currents
Why do large currents cause problems?
Why do large currents cause problems?
They heat resistance wire, changing its resistance
Unit of resistance
Unit of resistance
Ohms (Ω)
Variable resistor's purpose
Variable resistor's purpose
Control voltage and current values
Why start with small voltage values?
Why start with small voltage values?
Prevent wire heating and keep temperature constant
