For an ideal machine:

1. Output energy = Input energy
2. Output energy > Input energy
3. Output energy < Input energy
4. Work output >  Work input

Which of the following statements is incorrect?

1. For a machine, velocity ratio does not change.
2. Due to friction, mechanical advantage of a machine increases.
3. For an ideal machine, work output is equal to the work input.
4. For an ideal machine, mechanical advantage is numerically equal to the velocity ratio

If the effort needed is less than the load, then mechanical advantage of the machine is:

1. Greater than 1
2. Less than 1
3. Equal to one 
4. None of these

Select the incorrect statement:

1. A machine always has efficiency less than 100%.
2. The mechanical advantage of a machine can be less than 1.
3. A machine can have mechanical advantage greater than the velocity ratio.
4. A machine can be used as a speed multiplier.