Physics - Electrostatics + Current, Magnetism Flashcards
When two insulating materials are rubbed together, which particle is transferred between them?
An electron would transfer from one insulator to the other.
What sort of material does not allow charge to flow through it easily?
an insulator such as plastic or wood
A polythene rod is charged by friction and scraped across a nanocoloumbmeter, which charge will the nanocoulombmeter adopt?
Nanocoulombmeter becomes negatively charged
Explanation
Electrons transfer from the cloth to the polythene rod. The rod becomes negatively charged
These electrons transfers from the polythene rod to the nanocoulombmeter
Name three uses of electrostatics
- electrostatic smoke removal from chimneys
- photocopier
- inkjet printer
- electrostatic paint sprayer
Where are neutrons located in an atom?
the nucleus
What charge would a rod adopt if 3nC of electrons were transferred from a cloth to the surface of the rod?
- 3 nC
Describe what a gold leaf electroscope is.
A gold leaf electroscope is used to study electrostatic charge
It has a metal plate at the top which is connected to a metal post encased in a glass box. A piece of very thin gold foil is glued to the side of the metal post.
When charged- the metal rod and gold leaf have the same charge and repel, gold leaf moves up.
What is an induced charge? (Balloon + wall)
When a neutral object has a separation of charge within itself.
Electrons move from one side of the object to the other.
The side with more electrons is negatively charged
The side with fewer electrons is positively charged.
Overall the charge is neutral- charge is only displaced within the object itself
What would happen if two negatively charge balloons were hung side by side?
They would repel because like charges repel
What does the prefix nano stand for in 10 nC
nano is 10-9
or
10nC = 10 x 10-9 C
Explain why only electrons are transferred when objects are charged by friction.
Electrons are located in the outer shells of an atom and are easily removed.
However, protons are located in the nucleus at the centre of the atom and are tightly bound.
A negatively charge polythene rod is scraped across a gold leaf electroscope. The gold leaf rises.
What would you observe if the same thing was done with an acetate rod?
The gold leaf would rise just the same as it did with the polythene rod.
The gold foil is repelled from the central post in both cases as both the post and the gold leaf have the same charge.
A polythene rod is charged by friction and scraped across a nanocoloumbmeter, what charge will the nanocoulombmeter adopt?
Nanocoulombmeter becomes negatively charged
Explanation
Polythene gains electron from the cloth to become negatively charged
The electrons transfers from the polythene rod tot the nanocoulombmeter
What does the prefix micro stand for in 100 uA
micro is 10-6
or 1
00 uC = 100 x 10-6 C
Explain how a gold leaf electroscope works.
When it is charged, both the rod and leaf adopt the same charge and the gold leaf is repelled from the rod and rises.
The greater the charge, the greater the repulsion the further the gold foil rises.
A acetate rod is charged by friction and scraped across a nanocoloumbmeter, what charge will the nanocoulombmeter adopt?
Nanocoulombmeter becomes positively charged
Explanation
Acetate loses electron to the cloth to become positively charged
Electrons transfer from the nanocoulombmeter to the rod, leaving the nanocoulombmeter positive.
What does the prefix milli stand for in 65 mA
milli is 10-3
or
65 mC = 65 x 10-3 C
Where are protons located in an atom?
the nucleus
A polythene rod is rubbed with a cloth. What happens?
Electrons transfer from the cloth to the rod.
The polythene rod becomes negatively charged
The cloth becomes postively charged
Which sort of material allows charge to flow through it?
conductor such as a metal
What is the relative charge of an electron?
-1
What charge would a rod adopt if 5nC of electrons were transferred from its surface to a cloth?
+ 5 nC
What would happen if two positively charge rods were hung side by side?
The would repel because like charges repel
How can a charged object be discharged?
Earth it. Connect a wire conductor from the object to a stake in the ground.
What is the relative charge of a proton?
+1
What is the relative charge of neutron?
0
An acetate rod is rubbed with a cloth. What happens?
Electrons transfer from the rod to the cloth.
The acetate rod becomes positively charged
The cloth becomes negatively charged
Where are electrons located in an atom?
shells
What charge would a rod adopt if 5nC of electrons were transferred from its surface to a cloth?
+ 5 nC
Name three dangers of electrostatic charge
- Refueling cars or aircraft
- explosion of dust or fine powder in industry
- Lightning from charge build up in clouds
- Spark in operating theatre- explosion of oxygen
What can we use to measure charge?
A nanocoulombmeter
How can we reduce the electrostatic force acting on the objects below?
Move them further apart OR decrease their charge.
What would happen if a negatively charge rod and a positively charge rod were hung side by side?
The would attract because unlike/opposite charges attract
What are the ends of a bar magnet called?
north pole and south pole
In which region around a bar magnet is the magnetic field the strongest? How can the magnetic field lines indicate this?
The magnetic field is strongest at the poles, the field lines are close together at the poles indicating a stronger field.
How can you create a uniform field using two bar magnets?
Place the bar magnets so that the N pole of one magnet is facing the S pole of the other.
Move them so that they are close but not touching
There is a uniform field between the poles
Describe the magnetic field created when the N-pole of one bar magnet is near the S-pole of another.
Uniform field
Magnetic field lines are parallel AND evenly spaced
What is a magnetic field?
A region of space where a magnetic material experiences a force.
Name a metal which is magnetically hard.
Steel
Name a metal which is magnetically soft
iron
What is the point called between two adjacent N-poles of a magnet where their magnetic field cancels?
neutral point
What is the law of magnetism?
Like poles repel
Unlike poles attract
What is the difference between the domains in a magnetically hard material and a magnetically soft material?
Magnetically hard- difficult for domains to align in a field (also difficult for domains which are lined up to de-align)
Magnetically soft- easy for domains to align in a magnetic field and then de-align when field is removed.
What is a permanent magnet made of? Magnetically hard material or magnetically soft?
Magnetically hard- so that it does not lose its magnetism easily
How can you observe THE SHAPE of a magnetic field around a magnet?
- Pace paper over top the magnet
- Sprinkle iron filing on the paper
- Tap the paper to help the iron filings line up in the field
What happens when an iron nail is brought near the N Pole of a magnet.
The nail is attracted to the N-pole
The domains in the iron nail line up (point away) in the field creating a S-pole at the top of the nail closest to the magnet. (Magnetism is induced in the iron nail)
Opposite poles attract and the nail sticks to the magnet.
What is the difference in the orientation of the domains in a magnetised and demagnetised material?
Magnetised- domains are lined up
De-magnetised- domains are randomly arranged
How can you show the shape AND direction of a magnetic field around a magnet?
- place a magnet on a piece of paper
- place a plotting compass at one corner of the N-pole of the magnet
- draw a dot where the compass is pointing.
- move the compass forward so that the tail is adjacent to the point you just plotted
- draw another dot where the compass is pointing
- Continue this until you reach the S-pole and connect the dots with a smooth curve.
- Repeat steps 3-6 drawing multiple field line around the magnet
Draw an attracting field between a North and South pole.
idk how to draw this ☠️
Draw a repelling field between two N-poles
can’t draw this either soz ☠️
How can an iron nail be magnetised?
Stroke the iron nail with a magnet for several minutes.
This will align the domains in the iron nail and magnetise it.
How can you demagnetise a permanent magnet?
Heat it, hammer it or drop it repeatedly.
This will de-align the domains (demagnetise it)
In which direction do magnetic field lines run?
North to South
OUT of the North
INTO the South
What do we call it when ‘all’ the domains in a magnetic material are aligned and magnet cannot become any stronger?
saturated