Which of the following work is done by effort?
A) input work
B) output work
C) resultant work
D) useful work
Which of the following has 100% efficiency?
A) hydraulic machine
B) perfect machine
C) simple machine
D) compound machine
Velocity ratio of which machine is given by [tex]$\frac{l}{h}$[/tex]?
A) lever
B) inclined plane
C) pulley
D) wheel and axle
Answer (1)
Input work is done by effort.
A perfect machine has 100% efficiency.
The velocity ratio of an inclined plane is given by h l .
The answers are A, B, and B, respectively. A , B , B
Explanation
Understanding the Questions The question consists of three multiple-choice questions related to work, efficiency, and velocity ratio. We need to select the correct option for each question based on the definitions and principles of these concepts in physics.
Answering Question 1 For the first question, we need to identify the type of work that is directly associated with the effort applied. Input work is the work done by the effort.
Answering Question 2 For the second question, we need to determine which machine has 100% efficiency. A perfect machine is a theoretical concept that assumes no energy loss due to friction or other factors, thus having 100% efficiency.
Answering Question 3 For the third question, we need to identify the machine whose velocity ratio is given by the formula h l . This formula represents the velocity ratio of an inclined plane, where 'l' is the length of the inclined plane and 'h' is its height.
Final Answers Therefore, the answers are:
Which of the following work is done by effort? A) input work
Which of the following has 100% efficiency? B) perfect machine
Velocity ratio of which machine is given by h l ? B) inclined plane
Examples
Understanding the concepts of work, efficiency, and velocity ratio is crucial in designing and analyzing machines. For example, when designing a ramp (inclined plane) to load heavy objects onto a truck, engineers use the velocity ratio ( h l ) to determine the mechanical advantage and the force required to push the object. Similarly, understanding efficiency helps in optimizing machines to minimize energy loss and maximize output. These principles are also applied in everyday tasks, such as using levers to lift heavy objects or pulleys to raise loads, making our work easier and more efficient.
