WorksheetsBWS AQA Physics Electromagnetism Topic
Total questions: 25
Worksheet time: 13mins
A permanent magnet has which properties?
Produce their own magnetic fields
The magnetic fiield strength can be changed
Can attract and repel other magnets
Can be switched off and on
Opposite poles on a magnet will
Attract
Repel
An induced magnet has which properties?
Can only attract a magnet
Can attract and repel magnets
Loses their magnetism when removed from a magnetic field
Are only magnetic when in a magnetic field
Are made of all metals
Magnetic fields go in the direction?
South to North
North to South
They don't have fields
Downhill
Earth's geographical north is magnetic south - True or False?
True
False
A coil of wire with electricity travelling through it is called a ___________________?
Solenoid
Solaroid
Magnetoid
Coiloid
To make an electromagnet stronger you usually have what added through the middle of the coil?
A copper core
An iron core
A steel core
A plastic core
Flemming's left hand rule tell us which 3 things?
Direction of force
Direction of voltage
Direction of current
Direction of Magnetic field
Magnetic field strength
What is the unit of magnetic flux density?
Bertram
Newton
Tesla
Ampere
The force exerted by a magnetic field depends on 3 things. They are...
Total length of the wire
Length of the wire perpendicular to the magnetic field
Magnetic field strength
Electron density
Current
A split ring commutator in a DC motor does what?
A split ring commutator changes the direction of current every half turn
A split ring commutator changes the flow of voltage every half turn
A split ring commutator changes the force of power charge every half turn
A split ring commutator changes the curent of the voltage of the power every half turn
The direction of current, field and force on the wire in this diagram are incorrect.
True or false?
True
False
What angle must there be between a magnetic field and a conductor in order for the maximum force to be exerted?
180
45
90
270
Which action will increase the deflection of the galvanometer pointer? (A galvanometer measures the flow of small currents)
The magnetic pole is reversed
The number of turns of coils is increased
The coil is made from insulated wire
The magnet is slowly pushed into the coil
A voltage is created in a wire when...
it cuts through magnetic field lines
it moves parallel to magnetic field lines
it is stationary in a magnetic field
a wire moves anywhere
Choose the correct comparison of the motor and generator effects.
Motor effect: current + magnetic field = motion
Generator effect: motion + magnetic field = current
Motor effect: current + motion = magnetic field
Generator effect: motion + magnetic field = current
Motor effect: current + motion = magnetic field
Generator effect: motion + magnetic field = no effect
What type of current must be supplied to a loudspeaker for it to work?
Alternating current
Direct current
Which of the following devices uses the generator effect?
Loudspeaker
Microphone
Headphones
In a moving microphone, what causes the coil of wire to move in a magnetic field?
Alternating current
The sound waves hitting the diaphragm attached to the coil.
What factor of the ac current affects the frequency of the sound wave produced by a loud speaker?
Wavelength
Frequency
Amplitude
Which of the following do loudspeakers and headphones use to produce sound?
Electromagnets
Generator effect
Motor effect
Transformers
If a transformer reduces voltage, it is called a....................... transformer.
step left
step right
step up
step down
If a transformer increases voltage, it is called a ......... transformer.
step right
step left
step up
step down
A transformer has 500 turns on its primary coil and 100
turns on its secondary coil. An a.c voltage of 25 V is
connected across the primary coil.
What is the voltage across the secondary coil?
VSVP=NSNP=IPIS
5.0 V
12.5 V
50.0 V
175.0 V
Diagram shows a simple transformer. The bulb does
not light up. Which modification will cause the bulb to light up?
Replace the 6 V battery with a 9 V battery
Increase the number of turns of the primary coil
Decrease the number of turns of the primary coil
Replace the 6 V battery with a 6 V a.c power supply
