In a dynamo electric current is produced using the principle of:

Correct option is D

The correct answer is option (d)
In a dynamo, electric current is produced using the principle of electromagnetic induction.
Key Points:-

• Electromagnetic induction refers to the process by which a change in the magnetic field within a conductor induces an electric current.
• This principle was first discovered by Michael Faraday in the 1830s, and it is the foundational principle behind many electrical devices, including dynamos.

Information Booster:

• A dynamo consists of a coil of wire and a magnet.
  
• When the coil rotates within the magnetic field (or the magnetic field around the coil changes), the magnetic flux through the coil changes.
  
• According to Faraday's Law of Induction, this changing magnetic flux induces an electric current in the wire coil.
  The mechanical energy of the rotating coil is converted into electrical energy.