Question

A cycle dynamo works on the principle of _____
A. chemical effects of current
B. magnetic effects of current
C. electromagnetic induction
D. mechanical effects of current

Answer 1

Hint: A cycle dynamo is used to convert mechanical energy into electrical energy. Faraday's laws define the physical laws that govern the rules to convert mechanical energy into electrical energy. A cycle dynamo is used to power the lights on the cycle using the electrical energy produced by the dynamo.

Complete answer:
A cycle dynamo is a device which is used to harness the mechanical energy and convert it into electrical energy to utilize it in further applications. It consists of a permanent magnet in the middle of some coils of wire.
When a cycle moves, this permanent magnet rotates in the middle of coils of wire and produces a current in the wire which is ultimately fed into a circuit for further use.
The primary cause of generation of current is due to change in magnetic field produced by the rotating coil or permanent magnet. The magnetic flux through the coil changes as it is rotated and it leads to production of current in the nearby closed circuit.
This was explained by Faraday and was termed as the phenomenon of electromagnetic induction. Faraday’s law explained the direction of current induced and the magnitude of current induced using the rate of change of magnetic flux.
It does not involve any chemical, magnetic or mechanical effects of current.

Therefore, the correct option is (C).

Note:
The phenomenon of electromagnetic induction was explained by certain laws which are known as Faraday’s law of electromagnetic induction. These laws find their application in a number of instruments such as power transformers, electric motors and so on. Many musical instruments like electric guitar and electric violin are also based on the laws of electromagnetic induction.