Chapter 5: Current and Electricity Flashcards
What is voltage?
Voltage is the amount of energy transferred per coulomb of charge.
What is 1 volt equal to?
1 Joule per Coulomb
What equation links voltage, energy and charge?
Voltage = energy/charge
What is current?
The rate of flow of charge
What equation links current, charge and time?
Current = charge/time
How can the presence of current in a circuit be indicated?
By using lamps and LEDs
What does an ammeter do and how is it connected in a circuit?
An ammeter measures current, and it is connected in series.
What does a voltmeter do and how is it connected in a circuit?
A voltmeter measures the voltage and is connected in parallel.
What effect does changing the resistance in a circuit have on the current?
When the resistance increases, the current decreases. They are inversely proportional.
How does the resistance of a LDR vary with light intensity?
The resistance increases as light intensity decreases.
How does the resistance of a thermistor vary with temperature?
The resistance decreases as the temperature increases.
What is potential difference, in terms of energy transfer?
The joules of energy that are converted to heat and light per coulomb of charge passing through the component that you are measuring.
How does the current vary in a series circuit?
The current remains equal throughout the circuit.
What type of circuit is best for house lights and why? (Example)
Parallel, because then you can turn them on and off separately, and if one breaks, you can still use the other lights.
What is current measured in?
Amps
