What type of core is used to make an electromagnet?

What is a solenoid? Draw the magnetic field lines for a solenoid and a bar magnet. Compare the two and state one similarity.

What is the difference between a direct current and an alternating current? How many times does $AC$ used in India change direction in one second?

Why is the metallic body of electrical devices connected to the earth wire?

To find the direction of the magnetic field around a current-carrying conductor,we use Fleming's left-hand rule.

Name and state the rule to determine the direction of a force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it. Name a device that uses a current-carrying conductor and a magnetic field.