Force Fields
What is the name of the force that pulls things towards an object's centre?
Gravity
What happens to like charges?
repel
What is an electric current?
Flow of electrons
Does resistance makes it easier or harder for electrons to flow?
What field is created around a wire carrying a current?
magnetic field
What is the unit for weight?
Newtons (N)
Negative charges are electrons. What are positive charges?
nucleus (proton & neutron) OR positive ion
Where do we get energy from in a circuit?
battery/cell
What happens to current when resistance increases?
decreases
What do we call a coiled wire carrying current that acts like a magnet?
Electromagnet
Where is the magnetic field strongest on a magnet?
The poles
What is static electricity?
the build up of electric charge, causing forces of attraction and repulsion
Should a voltmeter be connected in series or parallel?
parallel to the component being measured
Which has lower resistance: a thick wire or thin wire?
thick wire
What happens to an electromagnet when the current is switched off?
It stops being magnetic
What is the formula for weight?
w = m × g
weight = mass × gravitational acceleration
Why does hair stand up for a little while after being rubbed by a balloon?
Each hair gets the same charge, and like charges repel in their field, so hairs repel each other
In a parallel circuit with 8 A total current and 2 equal branches, how much current flows in each branch?
4 A
Calculate the resistance if voltage is 12 V and current is 4 A
3 Ω
Name one way to increase the strength of an electromagnet
more current / more coils / add a magnetic core
What does gravitational field strength tell us?
how strong gravity pulls / how fast objects fall
Why can't conductors easily build up static charge?
Electrons flow away / charge escapes
In which type of circuit is the voltage the same across each component?
parallel
Why do we add resistors to circuits?
Keeps the current stable / Limits or controls electrical current and voltage in a circuit
What is the motor effect?
Force produced when a current-carrying wire is placed in a magnetic field