Hey rafik shaikh

Basically load torques are classified into two types that are:-

1. Active load torques

2. Passive load  torques

Firstly,load torque is the torque that is required for keep the application of load same at all the speeds and at various frictions.

firstly, if we talk about active load torque, it is the torque which has the capability to move or drive any motor like dc motor  under various equilibrium conditions.They only  retain thier signs when the direction is changed

Example - torque due to surface tension or torque due to compression etc

Now , as per as passive load torque is concerned, it is the torque which opposes the motion of the motor and when the motion is reversed, they changed their signs.

Example- torque due to friction etc.