GATE Mechanical Engineering

The endurance limit of a specific grade of steel is same as its yield strength. The ultimate strength of this grade of steel is twice of its yield strength. A component made of thi...

A pair of spur gears is required to maintain a velocity ratio of $1: 2$. The module of the gears is 10 mm and the addendum is 10 mm . If the operating pressure angle is $15^{\circ}...

A shaft carries a helical spur gear. Which one of the following bearings can NOT be used to support it?

For a ball bearing, the fatigue life in millions of revolutions is given by $L = \left(\frac{C}{P}\right)^n$, where $P$ is the constant applied load and $C$ is the basic dynamic lo...

Which one of the following failure theories is the most conservative design approach against fatigue failure?

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 CNC worktable is driven in a linear direction by a lead screw connected directly to a stepper motor. The pitch of the lead screw is 5 mm. The stepper motor completes one full rev...

The type of fit between a mating shaft of diameter $25.0^{\begin{matrix} +0.010 \\\ -0.010 \end{matrix}}$ mm and a hole of diameter $25.0^{\begin{matrix} +0.015 \\\ -0.015 \end{mat...

Which of the following methods can improve the fatigue strength of a circular mild steel (MS) shaft?

Which one of the following CANNOT impart linear motion in a CNC machine?

The principal stresses at a point in a critical section of a machine component are $${\sigma _1} = 60\,\,MPa,\,\,{\sigma _2} = 5\,\,MPa$$ and $${\sigma _3} = - 40\,\,MPa.$$ For the...

A single – plate clutch has a friction disc with inner and outer radii of $$20mm$$ and $$40$$ $$mm,$$ respectively. The friction lining in the disc is made in such a way that the c...

A machine component made of a ductile material is subjected to a variable loading with $${\sigma _{\min }} = - 50MPa$$ and $${\sigma _{\max }} = 50MPa.$$ If the corrected endurance...

In a structural member under fatigue loading, the minimum and maximum stresses developed at the critical point are $$50$$ $$MPa$$ and $$150$$ $$MPa,$$ respectively. The endurance,...

Which of the bearings given below SHOULD NOT be subjected to a thrust load?

The principal stresses at a point inside a solid object are $${\sigma _1} = 100\,\,MPa,\,\,{\sigma _2} = 100\,\,MPa$$ and $${\sigma _3} = 0\,\,MPa.$$ The yield strength of the mate...

A machine element is subjected to the following bi-axial state of stress: $$\,\,{\sigma _x} = 80MPa;\,\,{\sigma _y} = 20MPa;\,\,{\tau _{xy}} = 40MPa.$$ If the shear strength of the...

The uniaxial yield stress of a material is $$300$$ $$MPa.$$ According to Von mises criterion, the shear yield stress $$(in$$ $$MPa)$$ of the material is ___________.

Which one of the following is the most conservative fatigue failure criterion?

For ball bearings, the fatigue life $$L$$ measured in number of revolutions and the radial load $$F$$ are related by $$F{L^{1/3}} = K,$$ where $$K$$ is a constant. It withstands a...

A spur pinion of pitch diameter $$50$$ $$mm$$ rotates at $$200$$ $$rad/s$$ and transmits $$3$$ $$kW$$ power. The pressure angle of the tooth of the pinion is $${20^ \circ }$$. Assu...

Ball bearings are rated by a manufacturer for a life of $${10^6}$$ revolutions. The catalogue rating of a particular bearing is $$16$$ $$kN.$$ If the design load is $$2$$ $$kN,$$ t...

Which one of the following is NOT correct?

A pair of spur gears with module $$5$$ $$mm$$ and a center distance of $$450mm$$ is used for a speed reduction of $$5:1$$. The number of teeth on pinion is _________

In a structure subjected to fatigue loading, the minimum and maximum stresses developed in a cycle are $$200$$$$MPa$$ and $$400MPa$$ respectively. The value of stress amplitude (in...

A shaft is subjected to pure torsional moment. The maximum shear stress developed in the shaft is $$100$$ $$MPa.$$ The yield and ultimate strengths of the shaft material in tension...

The state of stress at a point is given by $$\,\,{\sigma _x} = - 6\,MPa,\,\,{\sigma _y} = 4\,\,MPa,$$ and $${\tau _{xy}} = - 8\,\,MPa.$$ The maximum tensile stress (in MPa) at the...

A disc clutch with a single friction surface has coefficient of friction equal to $$0.3.$$ The maximum pressure which can be imposed on the friction material is $$1.5$$ $$MPa.$$ Th...

A hydrodynamic journal bearing is subject to $$2000$$ $$N$$ load at a rotational speed of $$2000$$ $$rpm.$$ Both bearing bore diameter and length are $$40mm.$$ If radial clearance...

A rotating steel shaft is supported at the ends. It is subjected to a point load at the center. The maximum bending stress developed is $$100 MPa.$$ If the yield, ultimate and corr...

A bolt of major diameter $$12$$ $$mm$$ is required to clamp two steel plates. Cross sectional area of the threaded portion of the bolt is $$84.3$$ $$m{m^2}$$ . The length of the th...

A bar is subjected to fluctuating tensile load from $$20$$ $$kN$$ to $$100$$ $$kN.$$ The material has yield strength of $$240$$ $$MPa$$ and endurance limit in reversed bending is $...

A solid circular shaft needs to be designed to transmit a torque of $$50$$ $$N.m.$$ If the allowable shear stress of the material is $$140$$ $$MPa,$$ assuming a factor of safety of...

The homogeneous state of stress for a metal part undergoing plastic deformation is $$$T = \left( {\matrix{ {10} & 5 & 0 \cr 5 & {20} & 0 \cr 0 & 0 & { - 10} \cr } } \right)$$$ Wher...

Two identical ball bearings $$P$$ and $$Q$$ are operating at loads $$30kN$$ and $$45kN$$ respectively. The ratio of the life of bearing $$P$$ to the life of bearing $$Q$$ is

Tooth interference in an external involute spur gear pair can be reduced by

A band brake having band-width of $$80mm,$$ drum diameter of $$250mm,$$ coefficient of friction of $$0.25$$ and angle of wrap of $$270$$ degrees is required to exert a friction tor...

A forged steel link with uniform diameter of $$30mm$$ at the centre is subjected to an axial force that varies from $$40kN$$ in compression to $$160kN$$ in tension. The tensile $$\...

A $${20^ \circ }$$ full depth involute spur pinion of $$4mm$$ module and $$21$$ teeth is to transmit $$15kW$$ at $$960rpm.$$ Its face width is $$25mm.$$ Given that the tooth geomet...

A $${20^ \circ }$$ full depth involute spur pinion of $$4mm$$ module and $$21$$ teeth is to transmit $$15kW$$ at $$960rpm.$$ Its face width is $$25mm.$$ The tangential force transm...

A journal bearing has a shaft diameter of $$40mm$$ and a length of $$40mm.$$ The shaft is rotating at $$20$$ $$rad/s$$ and viscocity of the lubricant is $$20mPa.s.$$ The clearance...

A spur gate has a module of $$3mm,$$ number of teeth $$16,$$ a face width of $$36mm$$ and a pressure angle of $${20^ \circ }$$. It is transmitting a power of $$3KW$$ at $$20rev/s.$...

Match the type of gears with their most appropriate description Type of gear (P)$$\,\,\,\,\,$$ Helical (Q)$$\,\,\,\,\,$$ Spiral Bevel (R)$$\,\,\,\,\,$$ Hypoid (S)$$\,\,\,\,\,$$ Rac...

A clutch has outer and inner diameters $$100mm$$ and $$40mm$$ respectively. Assuming a uniform pressure of $$2MPa$$ and coefficient of friction of inner material $$0.4,$$ the torqu...

A gear set has a pinion with $$20$$ teeth and a gear with $$40$$ teeth. The pinion runs at $$30rev/s$$ and transmits a power of $$20KW$$. The teeth are on the $${20^ \circ }$$ full...

A thin spherical pressure vessel of $$200mm$$ diameter and $$1mm$$ thickness is subjected to an internal pressure varying from $$4$$ to $$8MPa.$$ Assume that the yield, ultimate an...

A gear set has a pinion with $$20$$ teeth and a gear with $$40$$ teeth. The pinion runs at $$30rev/s$$ and transmits a power of $$20KW$$. The teeth are on the $${20^ \circ }$$ full...

A gear set has a pinion with $$20$$ teeth and a gear with $$40$$ teeth. The pinion runs at $$30rev/s$$ and transmits a power of $$20KW$$. The teeth are on the $${20^ \circ }$$ full...

A ball bearing operating at a load $$F$$ has $$8000$$hours of life. The life of the bearing, in hours, when the load is doubled to $$2F$$ is

A natural feed journal bearing of diameter $$50mm$$ and length $$50mm$$ operating at $$20$$ revolutions/sec carries a load of $$2kN$$. The lubricant used has a viscosity of $$20mPa...

A $$60mm$$ long and $$6mm$$ thick fillet weld carries a steady load of $$15kN$$ along the weld. The shear strength of the weld material is equal to $$200MPa.$$ The factor of safety...

Twenty degree full depth involute profiled $$19$$-tooth pinion and $$37$$-tooth gear are in mesh. If the module is $$5mm,$$ the center distance between the gear pair will be

A disk clutch is required to transmit $$5$$ $$kW$$ at $$2000$$ $$rpm$$ the disk has a friction lining with Coefficient of friction equal to $$0.25.$$ Bore radius of friction lining...

A cylindrical shafts is subjected to an alternating stress of $$100MPa.$$ Fatigue strength to sustain $$1000$$ cycles is $$490MPa.$$ If the corrected endurance strength is $$70MPa,...

Which one of the following is criterion in the design of hydrodynamic journal bearings?

Two mating spur gears have $$40$$ and $$120$$ teeth respectively. The pinion rotates at $$1200$$ $$rpm$$ and transmits a torque of $$20N.m.$$ The torque transmitted by gear is

The $$S$$-$$N$$ curve for steel becomes asymptotic nearly at

In terms of theoretical stress concentration factor $$\left( {{k_t}} \right)$$ and fatigue stress concentration factor $$\left( {{k_f}} \right),$$ the notch sensitivity $$'q'$$ is...

In a band brake the ratio of tight side band tension to the tension on the slack side is $$3.$$ If the angle of overlap of band on the drum is $${180^ \circ }$$ the coefficient of...

A static load is mounted at the center of a shaft rotating at uniform angular velocity. This shaft will be designed for

The minimum number of teeth on the pinion to operate without interference in standard full height involute teeth gear mechanism with $${20^ \circ }$$ pressure angle is

Large speed reductions (greater than $$20$$) in one stage of gear train are possible through

A $$1.5$$ $$kW$$ motor is running at $$1440$$ rev/min. It is to be connected to a stirrer running at $$36$$ rev/min. the gearing arrangement suitable for this application is

The life of a ball bearing at a load of $$10$$ $$kN$$ is $$8000$$ hours. Its life in hours, if the load is increased to $$20$$ $$kN,$$ keeping all other conditions same, is

Bolts in the flanged end of pressure vessel are usually pre- tensioned. Indicate which of the following statements is not true

The basic load rating of a ball bearing is

Which theory of failure will you use for aluminium components under steady loading is

The dynamic load capacity of $$6306$$ bearing is $$22KN.$$ The maximum radial load it can sustain to operate at $$600$$ $$rev/min,$$ for $$2000$$ hours is

To make a worm drive reversible, it is necessary to increase

To restore stable operating condition in a hydrodynamic journal bearing, when it encounters higher magnitude loads.

Match the following List - $${\rm I}$$ (a)$$\,\,\,\,\,$$ Automobile wheel mounting on axle (b)$$\,\,\,\,\,$$ High speed grinding spindle (c)$$\,\,\,\,\,$$ $${\rm IC}$$ - Engine con...

A small element at the critical section of a component in bi-axial state of stress with the two principal stresses being $$360$$ $$MPa$$ and $$140$$ $$MPa.$$ The maximum working st...

In thick film hydrodynamic journal bearings, the coefficient of friction

The bolts in a rigid flanged coupling connecting two shafts transmitting power are subjected to

In spur gears, the circle on which the involute is generated is called the

If the ratio of the diameter of river hole to the pitch of rivets is $$0.25$$, then the tearing Efficiency of the joint is

A solid shaft can resist a bending moment of $$3.0$$ $$kNm$$ and a twisting moment of $$4.0$$ $$kNm$$ together, then the maximum torque that can be applied is

Match the following: List-$${\rm I}$$ (A) Worm gears (B) Cross helical gears (C) Bevel gears (D) Spur gears List-$${\rm I}{\rm I}$$ 1. Parallel shafts 2. Non-parallel, intersecting...

Interference in a pair of gears is avoided, if the addendum circles of both the gears intersect common tangent to the base circles with in the points of tangency.

Two shafts $$A$$ and $$B$$ are made of the same material. The diameter of shaft $$B$$ is twice that of shaft $$A.$$ The ratio of power which can be transmitted by shaft $$A$$ to th...