| Quiz | Magnetism and electromagnetism |
|---|---|
| Name | |
| Result | PASSED |
| Score | 26 / 26 (100%) |
| Passing score | 20.8 |
| Quiz took | 2 min 35 sec |
| Quiz finished at | 2025-02-16 19:31:48 |
Which of the following converts pressure variations of a sound wave into variations in current in an electric current?
Magnetic flux density can be measured in
The national grid uses step-up transformers to transmit power at __________ , as this wastes less energy as heat and is a more efficient way to transmit power.
There is a 230 V potential difference across the primary coil of a transformer and a 9 A current through this primary coil. There is a 12 A current through the secondary coil of the transformer. Calculate the potential difference across the secondary coil of the transformer.
Which of these is not a magnetic element?
An electromagnet is made using a solenoid and
AC generators use ___________ . Therefore, the contacts do not swap every half turn and an alternating potential difference is produced.
____________ can be used to decrease the potential difference.
Which of the following can be used to change the size of the potential difference?
The magnetic field around a wire with a current running through it, can represented using
Which of the following would not increase the size of the induced potential difference in a generator?
A 230 V potential difference is input into a transformer. The transformer has 50 turns on the primary coil and 120 turns on the secondary coil. Calculate the output potential difference.
An electric motor converts
A generator converts
The closer together field lines are, the _______ the magnetic field is
Which of the following generates direct current?
Transformers only work with
A basic loudspeaker can be made from an electromagnet and
In order to swap the contacts every half turn in a motor, we can use
When magnetic materials are put into a magnetic field, a magnet can be
When a current cuts through a magnetic field, you can find which way the force will act using
____________ can be used to increase the potential difference.
The frequency of a sound wave from a loudspeaker is controlled by the
Transformers consist of two coils and
A coil of wire can also be called a
Which of the following generates alternating current?