Locomotives with monomotor bogie have
Right Answer is:
Suitability for the passenger as well as freight service
A monomotor is a train design where a single traction motor powers two or three axles in the same bogie. Conventional bogie design involves either having one motor for each axle or having one or more axles unpowered. The monomotor design causes the motor to give both axles the same number of revolutions per minute.
The monomotor design makes it relatively easy to fit a locomotive with two-speed gearing. Low gear is used when hauling freight trains and high gear is used when hauling express passenger trains.