Electromagnetism

Step 1: Understanding the Concept:
An electric generator operates on the principle of electromagnetic induction.

Step 2: Detailed Explanation:
In a generator, a coil is physically rotated inside a magnetic field using some external mechanical force (like a turbine driven by water or steam).
This mechanical rotation changes the magnetic flux linked with the coil, inducing an electromotive force (EMF) and generating an electric current.
Therefore, the input is physical motion, and the output is electricity.

Step 3: Final Answer:
Mechanical energy is converted into electrical energy.

Step 1: Understanding the Concept:
A solenoid is a long coil of wire.
When current flows through it, it behaves like a bar magnet with distinct North and South poles.

Step 2: Detailed Explanation:
Outside a magnet (or solenoid), magnetic field lines travel from the North pole to the South pole.
Since magnetic field lines form continuous closed loops, they must travel from the South pole to the North pole inside the solenoid to complete the loop.
The lines inside are parallel and straight, indicating a uniform magnetic field.

Step 3: Final Answer:
The direction is from South to North inside the solenoid.