| Quiz | Magnetism and electromagnetism |
|---|---|
| Name | |
| Result | FAILED |
| Score | 20 / 26 (76.9%) |
| Passing score | 20.8 |
| Quiz took | 22 min 34 sec |
| Quiz finished at | 2022-10-15 14:58:24 |
Which of the following generates direct current?
Transformers only work with
The closer together field lines are, the _______ the magnetic field is
In order to swap the contacts every half turn in a motor, we can use
Which of the following converts pressure variations of a sound wave into variations in current in an electric current?
AC generators use ___________ . Therefore, the contacts do not swap every half turn and an alternating potential difference is produced.
A generator converts
A basic loudspeaker can be made from an electromagnet and
The frequency of a sound wave from a loudspeaker is controlled by the
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.
A coil of wire can also be called a
Magnetic flux density can be measured in
Which of the following can be used to change the size of the potential difference?
Transformers consist of two coils and
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.
Which of the following generates alternating current?
When magnetic materials are put into a magnetic field, a magnet can be
____________ can be used to increase the potential difference.
____________ can be used to decrease the potential difference.
Which of these is not a magnetic element?
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 would not increase the size of the induced potential difference in a generator?
An electromagnet is made using a solenoid and
The magnetic field around a wire with a current running through it, can represented using