Physics 5054 · O Level · Forces on a current-carrying conductor
Forces on a current-carrying conductor — practice question
Fig. 7.1 shows a section of a loudspeaker. A coil is fixed to a paper cone and hangs freely inside a cylindrical magnet.
(a)[2]
Explain why a current in the coil makes the paper cone move.
(b)[2]
Describe and explain the motion of the cone when the current in the coil is alternating.
(c)[2]
The loudspeaker emits sound with frequency $500\,\text{Hz}$. The speed of sound is $320\,\text{m s}^{-1}$. Calculate the wavelength of the sound produced.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Current in a coil produces a magnetic field” …