C4 Motor Effect Flashcards
Define the Motor Effect
When a wire carrying a current interacts with another magnetic field, at right angles, causing a force that moves the wire.
List 3 ways to increase the force of a motor effect
- the current in the wire increases;
- the strength of the magnetic field increases;
- the length of wire inside the magnetic field is increased.
What is a Direct Current?
The flow of charge is going in 1 direction only
What is Alternating Current?
The flow of charge is going in both directions
Is mains power supply A.C or D.C?
A.C (Alternating Current)
What voltage is mains electricity?
230 Volts
What Frequency is mains electricity?
50 Hz
How can you change the direction a coil is moving in a motor?
- reversing the direction of the current OR
- reversing the direction of the magnetic field (changing over the north and south poles).
List 2 way you can increase the speed in a motor?
- increasing the size of the current;
-using a stronger magnet; - increasing the number of turns of wire in the coil;
- reducing friction between the coil and the axel it rotates on.
What 3 materials are induced magnets made out of?
Iron, Nickel, Cobalt
How can you induce an induced magnet?
Put it in the presence of a permeant magnet.
True of False: A permeant magnet will always experience attraction when in presence of a induced magnet.
True
List 2 ways to increase the strength of an electromagnet.
- Add an iron core
- Increase current
What is a solenoid?
The coil of wire surrounding an iron core
List 3 examples of electromagnetic radiation
Any of:
- Radiowaves (VHF, UHF)
- Microwaves
- UV Waves
- X-Rays
- IR Radiation
-
How many cells make up a battery?
2
List a type of an A.C generator
Any of:
- Alternator (Synchronous Generators)
- Induction (Asynchronous Generators)
- Single Phase (Permanant Magnet Alternator)
What is the equation for an A.C generator current-time graph?
Any of:
- (y=x^{2}+3x)
- y = x^2 + 3x
What is mutual induction?
Mutual induction is where a change in the electric current in one coil (the primary coil) induces a voltage in a nearby coil (the secondary coil)
True of False: Mutual Induction can only occur in electromagnets with an A.C power supply
False
When a solenoid experienced static electricity, what effect with this have on the current?
The current will become negative causing a change in direction with the current.
Does a step up transformer increase or decrease current?
Decrease
Does a step down transformer increase or decrease potential difference?
Decrease
Is the potential difference in a pylon high or low?
Extremely high
Is the current in a pylon high or low?
Low
Fill in the gap: Metals conduct electricity due to _________ electrons.
Delocalised
