Initial tension in the belt:
Sol: The tension in belt which is passing over the two pulleys (that is driver and follower) when the pulleys are stationary is an initial tension in belt.
When the power is transmitted from one shaft to the other shaft with the help of belt, which passes over the two pulleys that are keyed, to the driver and driven shafts, there should be firm grip between pulleys and belt. When the pulleys are stationary, this firm grip is increased, by tightening two ends of belt. Thus the belt is subjected to tension. This tension is called as initial tension in belt.
Let To = initial tension in belt
T1 = Tension in tight side
T2 = Tension in slack side
To = (T1 + T2)/2