Taking Measurements In Circuits Flashcards
What is the unit for current?
Th unit for current is ampere (A) or Amp.
What do we use to use to measure current?
Current is measured with an ammeter.
What do we mean by voltage or potential difference?
It’s the measure of the ability of the electrons to move from the negative terminal of a battery to the positive terminal.
What is the difference between current and voltage?
Current is a measure of the number of electrons flowing along a wire.
Voltage is a measure of the ability of the electrons to do a particular task.
What is the unit for voltage?
The unit for voltage is volts (v).
What do we use to measure voltage?
Potential difference is measure using a voltmeter.
Cell:
Single unit of a device that converts chemical energy into electrical energy. Different cells produce different voltages. The bigger the voltage supplied by the cell, the bigger the current (the cell gives a bigger push to the electrons).
Battery:
A collection of cells that converts chemical energy into electrical energy.
What is electrical resistance?
The opposition to the movement of electrons is called resistance. We say that good conductors have a low resistance and not so good conductors have a higher resistance.
Electrons find it…
Easier to flow along some conducting materials than others.
All conducting materials…
Try to oppose the moving electrons.
What is the unit for resistance?
The unit for resistance is the ohm.
What do we use to measure resistance?
Resistance is measured with an ohmmeter.
Whatever current leaves…
The battery, the same current returns to the battery.
Voltage gets used…
Up as the current flows round the circuit.
Measuring current (parallel and series circuit: a summary):
Series circuit: Current is the same at all points in the circuit.
Parallel circuit: Current is shared between the components.
Measuring voltage (a summary):
Unlike an ammeter, a voltmeter is connected across components (in a parallel circuit).
To calculate voltage:
Current x Resistance
To calculate current:
Voltage divided by resistance
To calculate resistance:
Voltage divided by current
