Magnetic Effects of Electric Current — Important Questions

Emerge from the north pole, Merge at the south pole, Form closed curves

Magnetic field lines emerge from the north pole, merge at the south pole, and form closed curves. They never cross each other as this would mean a compass needle pointing in two directions at once, which is impossible.

True

The magnetic field inside a solenoid consists of parallel straight lines, indicating that the field is uniform (same strength and direction) at all points inside the solenoid.

Appears as straight lines at the center, Is stronger at the center than at the edges, Has the same direction from all parts of the loop at the center

At the center of a circular loop, the magnetic field lines appear straight because the arcs of concentric circles become very large. The field is stronger at the center, and all parts of the loop contribute to the field in the same direction at the center.

220 V

In India, the standard domestic electric supply provides 220 V potential difference between the live wire (red insulation) and neutral wire (black insulation) with a frequency of 50 Hz.