In an induction motor, no-load the slip is generally

In an induction motor, the slip is defined as the difference between the synchronous speed and the actual rotor speed, expressed as a percentage of the synchronous speed. At no-load conditions, the slip of an induction motor is typically very small because the rotor speed is very close to the synchronous speed.

Less than 1 %: At no-load, the slip is generally less than 1% because the rotor speed approaches the synchronous speed very closely when the motor is not under load.

1.5 %, 2 %, and 4 %: These values are higher and more characteristic of conditions when the motor is under load. At no-load, these slips would be too high, which does not align with the typical performance of induction motors at no-load conditions.

Thus, Option A: Less than 1 % is the correct choice.