Chapter 24.2, Problem 24PP

To determine

The way to orient magnetic field so that plate vibrated and produces sound.

Explanation of Solution

Introduction:

When current fluctuates through a coil, a temporary electromagnet is formed which is repelled and attracted by permanent magnet. With the motion of the coil, the cone also oscillates which generates sound wave in the air.

For plate to vibrate and produce sound, one pole must be kept close to the coil such that the magnetic field lines are at right angle to both the wires and the direction in which the plate moves.