Moving-coil ammeter: Primarily used for direct current (DC) only, as it relies on a constant magnetic field and does not accurately respond to AC. Moving-iron ammeter: Suitable for measuring both AC and DC currents. It operates based on the magnetic effect of the current, making it effective for AC. Hot-wire ammeter: Specifically designed for measuring AC currents. It utilizes the heating effect of the current and provides accurate readings for AC.