click below
click below
Normal Size Small Size show me how
CP10F
GCSE Combined Science Physics
Question | Answer |
---|---|
Why is a bar magnet a permanent magnet? | " It is always magnetic |
" What materials do magnets attract and which ones are they? | "Iron, Steel, Cobalt and Nickel |
" What is a magnetic field? | " The space around a magnet where it can attract magnetic materials. |
" Which poles attract and which repel? | "North and south attract, North and North repel and South and South repel |
" "What is an induced magnet? | " "When a piece of magnetic material is in a magnetic field it becomes a magnet itself. It stops when it is taken out of the field. |
" What instrument do we use to find the shape of a magnetic field? | "A plotting compass |
" What is a compass? | "It is a very small magnet that can move freely, it point to a position very near to the Earth’s geographic North pole. |
" "Describe the Earth’s magnetic field. | " "It is the same shape as a bar magnets field but the acts as if the South pole of the bar magnet in the Northern hemisphere. This makes sure the North pole of a compass points North. |
" If the field line are close together is this a strong or weak field? | Strong |
What does a current flowing through a wire produce around the wire? | A Megnetic field |
What is the shape of a magnetic field around a wire? | It circular |
If the direction of the current is reversed what happens to the magnetic field? | The magnetic field reverses |
What can you use to find the direction of the magnetic field? | Plotting compass. |
How can tell if the magnetic field is strong or weak from a field line diagram? | If the lines are close together it is strong, far apart weak. |
If a wire is made into coil and a current passes though it what is it called? | Solenoid |
Where is the magnetic field uniform in a solenoid? | "Near the centre where the field lines are parallel ( equally spaced) |
" What does the strength of the solenoid depend upon? | Size of the current |
"How could you change the solenoid to make it stronger? | " "Higher current , more coils closer together, insert an iron core. |
" Two like poles always ______ | repel |
Tow opposite poles always _______ | attract |
What is a permanent magnet? | A magnet that produces its own magnetic field. |
What is an induced magnet? | A magnetic material which becomes a magnet when placed in a magnetic field. |
A magnetic material which becomes a magnet when placed in a magnetic field is a _______ _________ | induced magnet |
What type of magnet loses its magnetism when it is removed from a magnetic field? | induced magnet |
Which three elements are magnetic? | iron, cobalt and nickel |
Draw the magnetic field around a bar magnet | teacher to draw on board… |
Give the name for the magnet created using a coil of wire | solenoid |
Where is the strongest field in an electromganet created by a coil of wire? | inside the coil |
What two words describe the magnetic field within the coil of a solenoid? | strong and uniform |
What is an electromagnet? | A solenoid containing an iron core which increases its strength |
What is an important property of a solenoid/electromagnet as a magnet | can be switched on and off with electric current |
Flemming's left hand rule shows the relative directions of what things? | Force, magnetic field and current |
In Flemming's LH rule, the thumb gives the direction of … | Force |
In Flemming's LH rule, the second finger gives the direction of … | Current |
In Flemming's LH rule, the first finger gives the direction of … | Magnetic Field |
When a conductor carrying a current is placed in a magnetic field, the magnet and the conductor …. | exert an equal and opposit force on one another |
Give three ways of increasing the force of a solenoid. | Add iron core, increase number of coils of wire, increase current, move magnetic material closer |
Give three ways of increasing the force of a motor. | Increase the number of coils of wire, increase the strength of the magnetic field, increase the current |
What is the unit of magnetic flux density? | Tesla (T) |
What two methods can you use to obesrve the field around a bar magnet? | Iron filings or plotting compass |
Draw the magnetic field between two like poles. | teacher to draw on board… |
Draw the magnetic field between two unlike poles. | teacher to draw on board… |
The right hand thumb rule shows relative direction of… | current and magnetic field around a wire |
The strength of magnetic field surrounding a conducting wire depends on… | Size of current and distance from wire |
State the equation which links current, force, length of conductor and magnetic flux density | F=BIl |
Which rule can be used to determine the direction a motor will rotate? | Flemming's left hand rule. |