Choose the correct alternatives (MCQs):

1. Which of the following formulae can give the value of the velocity ratio of the wheel and axle?
A) [tex]$\frac{1}{1 V}$[/tex]
B) [tex]$\frac{l}{h}$[/tex]
C) [tex]$\frac{ R }{ r }$[/tex]
D) [tex]$\frac{ T }{ R }$[/tex]

2. Which of the following is an example of a wheel and axle?
A) staircase
B) screwdriver
C) scissors
D) nut-cracker

3. Which ratio of the following is given by mechanical advantage?
A) two forces
B) two works
C) two distances
D) two loads

4. Which of the following is velocity ratio?
A) [tex]$\frac{ L }{ E }$[/tex]
B) [tex]$\frac{ Ld }{ Ed }$[/tex]
C) [tex]$\frac{ Ed }{ Ld }$[/tex]
D) [tex]$\frac{ E }{ L }$[/tex]

5. Which of the following is affected by friction?
A) VR
B) efficiency
C) MA
D) B and C both

6. Which of the following work is done by effort?
A) input work
B) output work
C) resultant work
D) useful work

7. Which of the following has 100% efficiency?
A) hydraulic machine
B) perfect machine
C) simple machine
D) compound machine

8. Velocity ratio of which machine is given by [tex]$\frac{l}{h}$[/tex]?
A) lever
B. inclined plane
C) pulley
D) wheel and axle

The multiple-choice questions cover the concepts of simple machines, velocity ratio, mechanical advantage, and efficiency.

The velocity ratio of a wheel and axle is r R ​ .
A screwdriver is an example of a wheel and axle.
Mechanical advantage is the ratio of two loads.
Velocity ratio is L d E d ​ .
Efficiency is affected by friction.
Input work is done by effort.
A perfect machine has 100% efficiency.
An inclined plane has a velocity ratio of h l ​ .

Explanation

Introduction We will address each multiple-choice question individually, providing the correct answer and a brief explanation.

Question a a) The velocity ratio (VR) of a wheel and axle is the ratio of the radius of the wheel (R) to the radius of the axle (r). Therefore, the correct formula is r R ​ .

Question b b) A screwdriver is a common example of a wheel and axle. The handle acts as the wheel, and the shaft acts as the axle.

Question c c) Mechanical advantage (MA) is the ratio of the load to the effort.

Question d d) Velocity ratio (VR) is the ratio of the distance moved by the effort to the distance moved by the load. VR = L o a dd i s t an ce E ff or t d i s t an ce ​ = L d E d ​ .

Question e e) Friction affects efficiency. It reduces the actual mechanical advantage and useful output.

Question f f) The work done by the effort is the input work.

Question g g) A perfect machine has 100% efficiency. This is a theoretical concept where there are no energy losses due to friction or other factors.

Question h h) The inclined plane has a velocity ratio of h l ​ , where l is the length of the inclined plane and h is the height.

Final Answer Here are the answers to the multiple-choice questions: a) C) r R ​ b) B) screwdriver c) D) two loads d) C) L d E d ​ e) B) efficiency f) A) input work g) B) perfect machine h) B) inclined plane


Examples
Understanding simple machines like the wheel and axle, inclined plane, and lever is crucial in everyday life. For instance, a screwdriver (wheel and axle) makes it easier to turn screws, reducing the effort needed. Similarly, ramps (inclined planes) allow us to move heavy objects to higher places with less force. These concepts are fundamental in engineering and physics, helping us design and use tools efficiently.

Answered by GinnyAnswer | 2025-07-08

The chosen answers for the MCQs are C) r R ​ , B) screwdriver, D) two loads, C) L d E d ​ , D) B and C both, A) input work, B) perfect machine, B) inclined plane regarding simple machines and their efficiencies.
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Answered by Anonymous | 2025-08-06