Font size
WorksheetsUnit 16
Total questions: 60
Worksheet time: 48mins
What is Magnetism?
It is a force of (a) or repulsion
Magnetism is cause by the movement of (a) particles
Magnetism is (a) charge
Magnetism is caused by the movement of (a)
What are the characteristics of magnets?
Attract iron, cobalt and (a)
Iron, cobalt and nickel are called (a) materials
A magnet has two (a)
Pole: Is the region on a magnet which produces (a) forces.
The magnetism of a magnet is strongest at either (a) of the magnet.
Like magnetic poles (a) each other and unlike magnetic poles attract each other.
Ferromagnetic materials can be attracted by (a) .
Magnetization: Objects (a) magnetism acquire magnetism.
Demagnetization: A magnetic object loses its (a) .
Does the magnet have to touch the paper clip to attract it?
Yes or No
(a)
Magnetic Field: The space around a magnet in which a magnetic (a) is exerted.
Magnetic field directed away from north poles and toward the (a) poles.
The strength of magnetic fields are measured in units of (T) (a)
In magnetism, every spinning electron is a tiny (a) .
Electrons spinning in the same direction produce a (a) magnet.
stronger or weaker
Earth itself is a huge (a) .
The magnetic field around the (a) is called geomagnetic field.
The direction of the magnetic needle is not due south or due north, but slightly deviates.
True or False
(a)
(a) is the first country in the world where people began to study the magnetic phenomenon.
The geomagnetic North pole is near the geographic South Pole.
True or False
(a)
There is a magnetic field around after current passes through a wire.
True or False
(a)
In generators, we use Fleming's (a) rule to indicate the direction of force, current and the direction of magnetic field.
To indicate the direction of current in a straight wire, we use the (a) in Ampere's right hand rule.
(which finger?)
The greater the current is, the _______________ the magnetism will be.
stronger
longer
shorter
weaker
The magnetic lines of induction are circles __________ to the wire.
parallel
perpendicular
along side
nect to
Density of the magnetic field means:
The farther away from the wire, the __________ the magnetism will be.
softer
louder
stronger
weaker
Electromagnetic relay 电磁继电器 is:
condenser
wire with current
electromagnetic switch
fly trap
Electromagnetic relay 电磁继电器:
can make the moon shine brighter
can turn on or off a much larger electric current.
can send electric current through rubber
can help to switch off and on the main switch
A relay circuit can be divided into two parts, the are called...
first and last circuits
twin loop circuits
primary and secondary circuits
None of them
The direction of the force acting on a wire in an electromagnetic field can be reversed by:
reversing the current
reversing the magnetic field
both of them
Which rule is used to find force in a DC motor?
Voltage left-hand
Ampere's left-hand
Fleming’s left-foot
Fleming’s left-hand
Flemings Left Hand Rule indicates the following...
Thumb - force
1st finger - Magnetic field
2nd finger - current
Thumb - heat
1st finger - Magnetic field
2nd finger - current
Thumb - force
1st finger - Magnetic field
2nd finger - voltage
Thumb - force
1st finger - Negative and Positive
2nd finger - current
An electric motor converts ___________ into mechanical energy for a turning effect.
heat energy
sun energy
electrical energy
water energy
Most motors are powered using ____________ (DC), which is produced by cells and batteries.
direct current
alternating current
upwards current
down current
What does AC stand for?
alternating voltage
alternating ohms
alternating resistance
alternating current
Name this rule use for generators.
Fleming’s right-finger
Fleming’s left-hand
Fleming’s right-hand
Ampere's right-hand
When current flows through a wire held in a magnetic field, a _________ is created that _____________the wire.
force / moves
movement / stop
cool / motion
motion / movement
If a wire is moved across a magnetic field, a current is produced. This is called ______________________.
electromagnetic sweeping
electromagnetic induction
electronic induction
electromagnetic waving
If curent and magnetic field move ______________ to each other, no current is induced.
vertical
side by side
parallel
perdendicular
A generator is a device that converts _______________ energy into electrical energy.
perpendicular
mechanical
floting
drifting
Power stations use generators to produce electricity on a large scale. Mechanical energy is provided by rotating turbines that can be powered by:
high-pressure steam – in coal, oil, gas and nuclear power stations
wind – in wind turbines
falling water – in hydroelectric power stations
all of it
When the plane of the coil is perpendicular to the magnetic field, the charged coil is subjected to the balance force and reaches the balance position.
At this time, due to ________, the coil will continue to rotate.
inertia
balance
top heavy
movement
Since "electricity" can generate "magnetism", "magnetism" can also generate "electricity"?
True or False
(a)
Using a magnetic field to generate electric current is called electromagnetic _________
little by little
more is less
sensitive information
induction
Make an easy drawing of a transformer.
Transformers only use _______ power.
DC
AC
CC
ABC
We discussed two types of transformers.
Step Up and step (a) transformers.
Explain Turbine
Spins around
moves up and down
A Transformer has a primary and a _______________ coil?
multiple
secondary
A transformer is:
a device that transfers .........
battery power
current in a wire
electric energy
magnetic force
Name the device in the picture.
Step down coil
Step down transformer
Battery support
Magnetic field
A (a) use a low-voltage circuit to control a high-voltage circuit.
Magnetic fields can only be produced by electro magnets.
True
False
Both
None of it
The ______________ in a DC motor is responsible for reversing the direction of the current.
coils
slip rings
commutator
rotor
In Amperes Right Hand Rule, the four fingers indicate the direction of magnetic field.
True
False
What is meaning of "DC" current?
(a)
