| Quiz | Magnetism and electromagnetism |
|---|---|
| Name | |
| Result | FAILED |
| Score | 19 / 26 (73.1%) |
| Passing score | 20.8 |
| Quiz took | 22 min 32 sec |
| Quiz finished at | 2024-03-09 08:48:02 |
Which of the following generates direct current?
A generator converts
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.
The frequency of a sound wave from a loudspeaker is controlled by the
A basic loudspeaker can be made from an electromagnet and
When magnetic materials are put into a magnetic field, a magnet can be
In order to swap the contacts every half turn in a motor, we can use
The magnetic field around a wire with a current running through it, can represented using
AC generators use ___________ . Therefore, the contacts do not swap every half turn and an alternating potential difference is produced.
Which of the following can be used to change the size of the potential difference?
The closer together field lines are, the _______ the magnetic field is
Which of these is not a magnetic element?
An electromagnet is made using a solenoid and
Magnetic flux density can be measured in
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.
A coil of wire can also be called a
Transformers only work with
____________ can be used to increase the potential difference.
Transformers consist of two coils and
Which of the following generates alternating current?
____________ can be used to decrease the potential difference.
Which of the following would not increase the size of the induced potential difference in a generator?
An electric motor converts
When a current cuts through a magnetic field, you can find which way the force will act using
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 the following converts pressure variations of a sound wave into variations in current in an electric current?