Question

-Match the correct function of machine:
a- it is used to obtain a gain in speed
b- it is used to lift a load in one direction
c- it can be used to overcome a load at some point by applying an effort at a convenient time
d- all of the above

Answer 1

Hint: A machine cannot perform work on its own. When we talk about an ideal machine then in that case work done on load will be equal to the work done by effort.

Complete answer: A machine is any mechanical device which does work. It cannot do work on its own. It has input and it does work and gives us some output. An ideal machine is one whose efficiency is 100% but it does not exist. It helps in gaining speed in a particular direction. It can have many levers but not all are force multipliers. Machines can perform work in lifting the load in a particular direction. Machine can change the direction of applied force, can change the magnitude of the force and can apply force at a convenient point. Thus, all the options are true, hence, the correct option is (d)

So, the correct answer is “Option D”.

Note:
Machines can be simple and complex. Examples of simple machines are levers, inclined planes etc. the work done by the machine is known as output energy and the work done on a machine is called input energy. The efficiency is an important parameter to judge the performance of the machine.