Question

A type of pulley is very often used as a machine even though it does not give any mechanical advantage.
i). Name the pulley Used.
ii). For what purpose is such pulley used.

Answer 1

Hint: Mechanical advantage signifies how much the input force has been amplified while using an instrument. The more the mechanical advantage, the more useful the instrument is. An instrument does not give any mechanical advantage if we need to apply a force that is originally needed to do a task. A simple pulley system is an example of this.

Complete step by step answer:
In the question, it is asked to mention a pulley system that does not give any mechanical advantage. The simple pulley is a pulley system which doesn’t provide any mechanical advantage to the user. Since we need to apply an amount of force on the rope to lift an object similar to the force, we need to apply to lift the same object directly from the ground. So, the pulley doesn’t give us an advantage in this case.
Nevertheless, these simple pulleys can be used to draw up objects from depth. Like drawing water from a well, it is difficult to draw water from the well with our hand using a bucket, but the bucket is tied to a rope, and the rope is cast over a pulley, it will be easier to use to draw water, still keep in mind the force applied is the same as drawing water from the well without the pulley.

Note: The single pulley system has a fixed axis of rotation. The load is attached to one end of the rope, and we apply force at the other end. So, only the direction of force is changing and not the magnitude.
As I mentioned in the answer, we can use the pulley to lift the object to above our height, but still, the force doesn’t change. Also, the mechanical advantage of the pulley is 1. So, there is no amplification of the applied force since the effort is equal to the load force.