# Electromagnets

Mind Map by Jack Milligan, updated more than 1 year ago
 Created by Jack Milligan over 4 years ago
7
0

JACK MILLIGAN

## Resource summary

Electromagnets
1. Right hand grip rule
1. Grab the wire with the right fist, thumb pointing up or down depending on current. (+ to -)
1. Curled finger direction shows direction of the magnetic field
1. Thumb shows direction of current
2. Flemings left hand rule
1. Forefinger points to Field (N to S)
1. thuMb points to Movement
1. seCond finger points to Current
2. Motor Effect
1. When a current flows in a magnetic field it will produce MOTION
1. A magnetic field is created when an electric current flows through a wire. Electromagnets have strong magnetic fields due to the coiling of wire around a soft iron core. . When a magnetic field from a wire is placed into another magnetic field, it causes the wire to move. This principle is utilised in electric motors and loudspeakers.
1. Electromagnets are used in many appliances including electric bells and relay switches
2. Strength of an elctromagnet increases when -
1. More coils
1. Larger current
1. Stronger magnets
2. Electromagnetic Induction
1. If we move a conductor in a magnetic field we will produce a current
1. 1. Wire is moved through magentic field
1. 2. This causes an electromagnetic field to be induced into the wire
1. 3. The EMF induces a current in the wire
1. 4. The current proiduces a magnetic filed which causes a 'drag' force in the wire in the opposite direction to the original motion.
2. Transformer Calculations
1. Transformers
1. Step up
1. More coiuls in secondary,
1. Increase voltage, decreases current
2. Step down
1. less coils in secondary
1. Decreases voltage, increase current

### Similar

AQA Physics P1 Quiz
Using GoConqr to study science
GCSE AQA Physics - Unit 3
GCSE AQA Physics 1 Energy & Efficiency
Waves
Forces and their effects
Junior Cert Physics formulas
Forces and motion
OCR Physics P4 Revision