| Quiz | Magnetism and electromagnetism |
|---|---|
| Name | |
| Result | FAILED |
| Score | 3 / 26 (11.5%) |
| Passing score | 20.8 |
| Quiz took | 2 min 20 sec |
| Quiz finished at | 2022-12-31 18:50:39 |
____________ can be used to decrease the potential difference.
Magnetic flux density can be measured in
When a current cuts through a magnetic field, you can find which way the force will act using
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.
AC generators use ___________ . Therefore, the contacts do not swap every half turn and an alternating potential difference is produced.
Which of the following generates direct current?
The closer together field lines are, the _______ the magnetic field is
An electromagnet is made using a solenoid and
____________ can be used to increase the potential difference.
Which of the following can be used to change the size of the potential difference?
A basic loudspeaker can be made from an electromagnet and
Transformers only work with
Transformers consist of two coils and
In order to swap the contacts every half turn in a motor, we can use
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?
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.
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?
When magnetic materials are put into a magnetic field, a magnet can be
An electric motor converts
Which of the following generates alternating current?
The frequency of a sound wave from a loudspeaker is controlled by the
A coil of wire can also be called a
Which of these is not a magnetic element?