Force fields and electromagnets Flashcards
When an acetate rod is rubbed with a duster the rod becomes positively charged. Where do the particles move from and to?
Electrons move from the rod to the duster
What charge does an object have if it loses electrons
Positive
What occurs when like charges move closer to each other
repulsion
Is plastic a good insulator
Yes
True or false, like charges repel
True
Friction causes the transfer of
Electrons
What do you use to measure current
Ammeter
what is the symbol for lamp
A circle with a cross inside
If resistance in a circuit is increased what happens to the current
It decreases
What are the units of electrical resistance
Ohms
What describes electrical resistance
A measure of opposition to the flow of electric current
What is current measured in
Amps (A)
Which type of circuit has components arranged in one loop
A series circuit
In parallel circuits the ______ is divided between branches
current
In a series circuit with a 9V battery and three bulbs what would the potential difference across each bulb be
3V
What happens to voltage in a series circuit
The voltage is split between the components
What happens to current in a series circuit?
It is the same in every part of the circuit
How would you best describe a parallel circuit
A circuit with mire than one route for the current to take
What happens to voltage in a parallel circuit
Voltage is the same across each path
How can you increase the strength of an electromagnet
Increase the amount of coils, increase current, increase the amount of iron
What advantage does an electromagnet have over a magnet
It can be switched on and off
National grid
The network of cables and transformers used to transfer electricity from power stations to consumers
