Question:
A square threaded screw is used to lift a load \( W \) by applying a force \( F \). Efficiency of square threaded screw is expressed as
A square threaded screw is used to lift a load \( W \) by applying a force \( F \). Efficiency of square threaded screw is expressed as
Show Hint
The efficiency of mechanical devices like screws can often be defined as the ratio of work done by the load to the work done by the applied force. Always check the given definitions carefully.
Updated On: Dec 15, 2025
- The ratio of work done by \( W \) per revolution to work done by \( F \) per revolution
- \( \frac{W}{F} \)
- \( \frac{F}{W} \)
- The ratio of work done by \( F \) per revolution to work done by \( W \) per revolution
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
The efficiency \( \eta \) of a square threaded screw is defined as the ratio of the work done by the load (\( W \)) to the work done by the applied force (\( F \)) for each revolution. This is expressed as:
\[
\eta = \frac{\text{Work done by } W}{\text{Work done by } F}
\]
Thus, the correct expression for efficiency is:
\[
\eta = \frac{W}{F}.
\]
Therefore, the correct answer is (A).
Was this answer helpful?
0
0
Top GATE Applied Mechanics and Design Questions
- A massive uniform rigid circular disc is mounted on a frictionless bearing at the end E of a massive uniform rigid shaft AE which is suspended horizontally in a uniform gravitational field by two identical light inextensible strings AB and CD as shown, where G is the center of mass of the shaft-disc assembly and g is the acceleration due to gravity. The disc is then given a rapid spin $\omega$ about its axis in the positive x-axis direction as shown, while the shaft remains at rest. The direction of rotation is defined using the right-hand thumb rule. If the string AB is suddenly cut, assuming negligible energy dissipation, the shaft AE will
- A structural member under loading has a uniform state of plane stress which in usual notations is given by $\sigma_x = 3P$, $\sigma_y = -2P$ and $\tau_{xy} = \sqrt{2}\,P$, where $P>0$. The yield strength of the material is 350 MPa. If the member is designed using the maximum distortion energy theory, then the value of $P$ at which yielding starts (according to the maximum distortion energy theory) is
- A square plate is supported in four different ways (configurations (P) to (S) as shown in the figure). A couple moment $C$ is applied on the plate. Assume all the members to be rigid and mass-less, and all joints to be frictionless. All support links of the plate are identical. The square plate can remain in equilibrium in its initial state for which one or more of the following support configurations?
- A rope with two mass–less platforms passes over a fixed pulley. Each disc weighs 20 N. For $n=5$ and $m=0$, a downward force $F = 200$ N applied on the right platform (figure (i)) is just sufficient to initiate upward motion of the left platform. If the force $F$ is removed (figure (ii)), the minimum value of $m$ required to prevent downward motion of the left platform is ______________ (in integer).
- A rigid homogeneous uniform block of mass 1 kg, height $h = 0.4$ m and width $b = 0.3$ m is pinned at one corner and placed upright in a uniform gravitational field ($g = 9.81$ m/s$^2$), supported by a roller as shown. A short duration impulsive force $F$, producing an impulse $I_F$, is applied at a height $d = 0.3$ m from the bottom. Assume all joints to be frictionless. The minimum value of $I_F$ required to topple the block is ________________.
View More Questions
Top GATE Kinematics and dynamics of rigid bodies in plane motion Questions
Consider the mechanism shown in the figure. There is rolling contact without slip between the disc and ground.
Select the correct statement about instantaneous centers in the mechanism.
The wheels and axle system lying on a rough surface is shown in the figure.
Each wheel has diameter 0.8 m and mass 1 kg. Assume that the mass of the wheel is concentrated at rim and neglect the mass of the spokes. The diameter of axle is 0.2 m and its mass is 1.5 kg. Neglect the moment of inertia of the axle and assume \( g = 9.8 \, \text{m/s}^2 \). An effort of 10 N is applied on the axle in the horizontal direction shown at mid span of the axle. Assume that the wheels move on a horizontal surface without slip. The acceleration of the wheel axle system in horizontal direction is \(\underline{\hspace{1cm}}\) m/s² (round off to one decimal place).
- A uniform light slender beam AB of section modulus \( EI \) is pinned by a frictionless joint A to the ground and supported by a light inextensible cable CB to hang a weight \( W \) as shown. If the maximum value of \( W \) to avoid buckling of the beam AB is obtained as \( \beta \pi^2 EI \), where \( \pi \) is the ratio of circumference to diameter of a circle, then the value of \( \beta \) is
- The plane of the figure represents a horizontal plane. A thin rigid rod at rest is pivoted without friction about a fixed vertical axis passing through O. Its mass moment of inertia is equal to 0.1 kg·cm² about O. A point mass of 0.001 kg hits it normally at 200 cm/s at the location shown, and sticks to it. Immediately after the impact, the angular velocity of the rod is ________________ rad/s (in integer).
- An L-shaped elastic member ABC with slender arms AB and BC of uniform cross-section is clamped at end A and connected to a pin at end C. The pin remains in continuous contact with and is constrained to move in a smooth horizontal slot. The section modulus of the member is same in both the arms. The end C is subjected to a horizontal force \( P \) and all the deflections are in the plane of the figure. Given the length AB is \( 4a \) and length BC is \( a \), the magnitude and direction of the normal force on the pin from the slot, respectively, are.
View More Questions
Top GATE Questions
- “I have not yet decided what I will do this evening; I ______ visit a friend.”
- Eject : Insert : : Advance : _______ (By word meaning)
- What are the number of numbers possible divisible by 3 if we choose 4 numbers from the set S = {4,5,7,8,9}
- Let \(A\) and \(B\) be real symmetric matrices of the same size. Which one of the following options is correct?
- Air inside a rigid, thermally-insulated tank undergoes stirring as shown in the figure below. Which one of the following options is correct?
\includegraphics[width=0.5\linewidth]{18.png}
View More Questions