Easter Revision Summary Sheets Paper Two Flashcards
Complete the gap fill :
Magnetic force is a type of ………. force and it is strongest at the ……. Of the magnet. There are two types of magnetic pole: a ……. …….. and a ….. ……
Non-contact
Poles
North Pole
South Pole
What is a magnetic field
The region around a magnet where a force acts on another object or on a magnetic material
What is a factor that affects the strength of the magnetic field
The strength of the magnetic field depends upon the distance from the magnet
List four magnetic materials
Iron
Steel
Nickel
Cobalt
What is the difference between a permanent magnet and an induced magnet
Permanent magnets produce their own magnetic field. Induced magnets become a magnet when placed in a magnetic field. However, when removed from the magnetic field an induced magnet loses most/all of its magnetism quickly.
How can the direction of a motor be reversed
By reversing the direction of the current or reversing the direction of the magnetic field
How can the speed of a motor be increased
By increasing the size of the current or increasing the magnetic field/ use a larger magnet
What rule can be used to find the direction of the force
Flemming’s left hand rule
What does each part of flemmings left hand rule represent
Thumb(held at 90 degrees)-force/thrust
First finger-field
Second finger-current
Why will a motor not work without a commutator
The commutator ensures that the current stays in the same direction, also the coil would not be free to spin. This means the coil would remain still and not rotate
What is a solenoid
A solenoid is turned when a long piece of conducting(and insulating) wire is looped into a coiled cylinder
How can you find the North Pole of a solenoid
Using the right hand grip method. Hold the solenoid with your right hand and finger pointing in the direction of the current is flowing. Your thumbs should point to the North Pole
What is the method that informs you could use to investigate the magnetic field.
Right hand grip method/rule
What do your thumb and fingers represent in the right hand grip method/rule
Thumb-direction of current
Fingers-the direction the field lines should be drawn
List four ways in which you can make the magnetic field around a solenoid/electromagnet stronger
Use longer current
Use an iron core
Add more turns to the wire
Place the turns of wire close together
Describe what happens to the magnetic field around a straight wire when the current is reversed
The magnetic field is also reversed
What is the motor effect
If a conductor carrying a current is placed in a magnetic field, the magnet producing the filed and the conductor exert a force on each other
Which type of wave are electromagnetic waves
Transverse waves
Which part of the EM spectrum can human eyes detect
Visible light only
What is the order of the electromagnetic spectrum
Radio waves-micro waves-infrared waves-visible light-ultraviolet waves-x rays-gamma rays
Explain radio waves and their uses
Television, radio and Bluetooth
The waves have low energy and so are not harmful for transmitting information over long distances
Explain microwaves and their uses
Satellite communication and cooking food
The water in the food absorbers the microwaves and heats up the food. Microwaves also travel in straight lines so are useful in communications
Explain infrared waves and their uses
Remote controls, infrared cameras and heaters
Very hot objects might glow, the wires in a toaster and transfer the heat energy to the food
Explain visible light and their uses
Optical fibres and photography(cameras)
The light wave is reflected inside of the fibre without being lost and so can carry data over long distances
Explain ultraviolet waves and their uses
Security marking, energy efficient lamps and sunbeds
Not visible too the human eye on banknotes and other documents so can help identify counterfeit or stolen goods
Explain x-rays and their uses
Medical imaging and medical treatment
X rays penetrate soft tissues but not through bones so an image can be formed
Explain gamma rays and their uses
Medical treatment for cancer and sterilising food
Higher frequency of all EM waves so will pass through plastic wrapping and metals to kill bacteria. Also kills cancer cells
Which type of EM wave has the longest wavelength
Radio waves
EM wave with highest frequency
Gamma rays
EM waves with shortest wavelength
Gamma rays
EM wave with lowest frequency
Radio wave
EM wave with most energy
Gamma rays
EM wave with least energy
Radio wave
Which type of EM wave can be produced by oscillations in electrical circuits
Radio waves
What can these radio waves also induce in electrical circuits
Oscillations
State four factors that are affected by different substance interacting with different EM waves
Absorbption
Reflection
Refraction
Transmitted
