What factor causes the current to decrease as an induction motor accelerates?

As an induction motor accelerates, the current drawn from the supply typically decreases due to the mechanical load on the motor. When an induction motor starts, it operates at a relatively high slip (the difference between synchronous speed and actual rotor speed), which means it draws a significant amount of current. However, as the motor accelerates and approaches its synchronous speed, the slip decreases. This reduction in slip leads to a decrease in the rotor current and, consequently, the stator current, which is primarily influenced by the mechanical load being driven.

As the load increases, the motor demands more current to maintain proper torque, while a decrease in load allows the motor to operate more efficiently, reducing the current draw. The external resistance and voltage are not the primary influences in this context, as they tend to stabilize or affect the starting torque rather than the current during the acceleration phase. The magnetic field remains relatively constant as well, as it is a function of the supply voltage and the design of the motor itself, rather than an influencing factor that changes during acceleration. Thus, the link between mechanical load and current draw during acceleration is the key reason for the decrease in current.