450-seconds rated motor is preferable for __________ A. Light

450-seconds-rated-motor-is-preferable-for-a-light

450-seconds rated motor is preferable for __________

A. Light duty cranes

B. Medium duty cranes

C. Intermittent duty cranes

D. Heavy duty cranes

I had been asked this question in an international level competition.

This intriguing question originated from Power Rating Determination of Electric Motors for Different Applications in chapter Rating and Heating of Motors of Electric Drives

Right answer is A. Light duty cranes

To elaborate: Light duty cranes are used in power plants, compressor plants. 450-seconds rated motor is preferable for light-duty cranes. They can safely operate for 450-seconds without exceeding the specified temperature.