What principle does a galvanometer operate on?

A galvanometer operates on the magnetic effect of electric current. When electric current flows through the coil of a galvanometer, it generates a magnetic field around it. This magnetic field interacts with a permanent magnet inside the device, resulting in a torque that causes the coil to rotate. The degree of rotation correlates directly with the amount of electric current flowing through the coil, allowing for the measurement of that current.

Understanding this principle highlights the importance of the magnetic fields created by current-carrying conductors and the interaction between these fields and magnetic materials. In contrast, the other choices do not accurately represent the operational principle of a galvanometer. The resistance of a conductor relates to how much current can flow but does not describe how a galvanometer functions. The inductive effect of electric current pertains to how an electric current can induce an electromotive force in a coil, which is not the primary principle used in galvanometers. Lastly, the capacitive properties of circuits involve the storage of electrical energy in an electric field and do not apply to the basic operation of a galvanometer.