Solenoids is used common used as electromagnets. It is also used in electromagnetic induction to show Faraday’s law and Lenz’s law. For inner solenoid, internal diameter is approximately 11 mm and external diameter is approximately 15 mm. For outer solenoid, internal diameter is approximately 24 mm and external diameter is approximately 30 mm. Number of turns on inner solenoid and outer solenoid are 200 and 370 respectively.