| Quiz | Magnetism and electromagnetism |
|---|---|
| Name | |
| Result | PASSED |
| Score | 22 / 26 (84.6%) |
| Passing score | 20.8 |
| Quiz took | 7 min 33 sec |
| Quiz finished at | 2023-12-18 17:57:17 |
Transformers consist of two coils and
Magnetic flux density can be measured in
When magnetic materials are put into a magnetic field, a magnet can be
A basic loudspeaker can be made from an electromagnet and
Which of these is not a magnetic element?
A coil of wire can also be called a
In order to swap the contacts every half turn in a motor, we can use
____________ can be used to decrease the potential difference.
An electric motor converts
AC generators use ___________ . Therefore, the contacts do not swap every half turn and an alternating potential difference is produced.
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.
An electromagnet is made using a solenoid and
The frequency of a sound wave from a loudspeaker is controlled by the
Which of the following generates alternating current?
Which of the following generates direct current?
Which of the following would not increase the size of the induced potential difference in a generator?
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 closer together field lines are, the _______ the magnetic field is
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 converts pressure variations of a sound wave into variations in current in an electric current?
When a current cuts through a magnetic field, you can find which way the force will act using
A generator converts
Which of the following can be used to change the size of the potential difference?
Transformers only work with
The magnetic field around a wire with a current running through it, can represented using
____________ can be used to increase the potential difference.