Answer:
16.Difference between a Bar Magnet and a Solenoid
The bar magnet is a permanent magnet whereas a solenoid is an electromagnet ie, it acts like a magnet only when an electric current is passed through. ... The poles of the bar magnet are fixed whereas for a solenoid the poles can be altered.
17.When you press a doorbell button, you complete an electrical circuit that allows household electricity to flow through the doorbell's internal electromagnet. The magnetic field generated by the electromagnet is then used to power a mechanism that creates the doorbell sound. Doorbells are low-voltage devices.
Explanation:
