A $$1.5$$ $$kW$$ motor is running at $$1440$$ rev/min. It is to be connected to a stirrer running at $$36$$ rev/min. the gearing arrangement suitable for this application is

To make a worm drive reversible, it is necessary to increase

In spur gears, the circle on which the involute is generated is called the

Interference in a pair of gears is avoided, if the addendum circles of both the gears intersect common tangent to the base circles with in the points of tangency.