Circuits + Fuses Flashcards
What kind of circuit is shown here, series or parellel?
Series
How does current vary in a series circuit?
The current is the same everywhere in a series circuit. It does not matter where you put the ammeter, it will give you the same reading.
What happens if one of the bulbs break in this series circuit?
The circuit will be broken and all the components stop working.
Wires are usually coated in plastic because?
Plastic is a good insulator of electricity
What happens to the current in a circuit if a bigger battery is used?
The current will increase
Wires are normally made from copper. This is because…
Copper is a very good conductor of electricity
Add a cell or batter AND close the switch
It will stay lit
An ammeter should always be connected in series
What device is used to measure the potential difference in a circuit and how should it be connected?
A voltmeter and it should be connected in parallel
They will read the same
What happens to a bulb connected to a battery when the potential difference is increased?
The bulb will get brighter.
Which has a greater resistance: a thick or a thin wire?
A thin wire.
Which one of these shows a resistor?
The one on the left
Why are fuses useful?
They protect electrical circuits and appliances from excessive current.
What is the difference between a fuse and a circuit breaker?
A circuit breaker can be reset while a fuse must be replaced.
If I rubbed two balloons with a piece of wool, what will happen when the balloons are brought near each other?
They would repel each other as each has gained negative static charge
When objects have equal numbers of positive and negative charges, they are ________
electrically neutral / no charge
Multiple cells connected together is called a _______
Battery
The flow of electrons in a circuit travels from the _______ terminal to the _______ terminal.
From the negative terminal to the positive terminal
The charge on an electron is?
Negative
Conventional current flows from the ________ terminal of a battery to the ________ terminal of a battery.
From the positive terminal to the negative terminal.
Electrical current is ____________
How fast the electrons flow around the circuit
Materials with very high resistances make good _______
Insulators. They do not let electricity pass through them easily.
What is the unit of resistance?
The Ohm
How does a fuse work to protect electrical equipment?
Fuses contain wires. If the current going through the fuse is too great, the wire heats up until it melts and breaks the circuit.
Which equation correctly links electric power P, voltage V and current I?
P = IV
A microwave has a power rating of 800 W. What size fuse should be used in the plug if the mains voltage is 240 V.
The fuse size should be 5 A.
Why should the fuse be rated at a slightly higher current than the device needs?
Otherwise the fuse would break as soon as the device was turned on.
