Efficiency of a Machine

Q. Difference between mechanical advantage and efficiency.

Q.

The ratio between the input energy to the output energy of a machine is called its efficiency.

1. True
2. False

Q.

The efficiency of a machine is the ratio of the work done on the load by the machine to the work done on the machine by the effort.

1. True

2. False

Q. If the efficiency of a machine is 40%, and it does 120 J of work, the input of the work would be:

1. 300 J
2. 500 J
3. 600 J
4. 800 J

Q.

What is a machine?

Q.

What is Efficiency of a machine?

Q.

Input is the work done_________ the machine and output is the work done____________the machine.

Q. What is the ratio of the output energy to the input energy of a simple machine?

Q.

The total input energy given to a machine cannot be equal to the total output energy. Explain.?

Q.

The efficiency of any machine is given by ___ .

1. $E=\frac{Effort}{Load}$

2. $E=\frac{V.R.}{MA}$

3. $E=\frac{Workinput}{Workoutput}$

4. $E=\frac{Workoutput}{Workinput}$ or $E=\frac{MA}{V.R.}$

Q. If the efficiency of a machine is 40%, and it does 120 J of work, the input of the work would be:

1. 300 J
2. 500 J
3. 600 J
4. 800 J

Q. If the efficiency of a machine is 40%, and it does 120 J of work, the input of the work would be:

1. 300 J
2. 500 J
3. 600 J
4. 800 J

Q.

Machines reduce the amount of work needed to do a job.

1. True

2. False

Q. Differentiate between mechanical advantage and efficiency. [2 MARKS]

Q.

What is SI unit for work and pressure.

Q.

Two machines A and B have efficiencies in the ratio 3:4. If the work done on machine A is 1200 J and on machine B is 1800 J, then what is the ratio of the work done by A to B