GATE 2021 ME : Toppers Quiz 30 (App update required to attempt this test) for ESE & GATE ME Exams

Question 1

Under ideal conditions, the velocity of steam at the outlet of a nozzle for a heat drop of 450 kJ/kg from inlet reservoir condition upto the exit is:

Question 2

Components produced by die casting have finer grain, higher strength and greater hardness at the skin than at the centre due to

Question 3

According to theorem of perpendicular axes, if I_xx and I_yy be the moment of inertia of a lamina about xx and yy axes, then moment of inertia of the lamina about zz axis, which is perpendicular to xx and yy, equal to

Question 4

The linear velocity of the centre of a rotating body is given by the relation

Question 5

In a polytropic process, the term

is equal to:

Question 6

The oil with specific gravity 0.8, dynamic viscosity of 8 × 10^–3 Ns/m² flows through a smooth pipe of 100 mm diameter and with Reynolds number 2100. The average velocity in the pipe is:

Question 7

In conventional refrigerants what is the element responsible for ozone depletion?

Question 8

Which one of the following statements is not correct for the exponential smoothing method of demand forecasting?

Question 9

An ideal Otto-cycle works between minimum and maximum temperature of 300 K and 1800 K. What is the compression ratio of the cycle for maximum work output when γ = 1.5 for this ideal gas?

Question 10

Instantaneous center of rotation of a link in a four-bar mechanism lies on

Question 11

The velocity at point (3,3) for the stream function ψ = –xln(xy) +x will be _________.

Question 12

Find the minimum number of stages required when air enters at 1 bar and 27°C and delivers at 260 bar. The maximum temperature at the outlet of compressor is limited to 327°C. Take the perfect intercooling in between stages and γ = 1.3.

Question 13

A copper tube of 20 mm outer diameter, 1 mm thickness and 20 m long (Thermal conductivity = 400 W/m-K) is carrying saturated steam at 150 C (Convective heat transfer coefficient = 150 W/m²-K). The tube is exposed to an ambient temperature of 27 C. The convective heat transfer coefficient of air is 5 W/m²-K. Glass wool is used for insulation (Thermal conductivity = 0.075 W/m-K). If the thickness of the insulation used is 5 mm higher than the critical thickness of insulation, calculate the rate of steam condensation in kg/hr-m (The enthalpy of condensation of steam = 2230 kJ/kg).

Question 14

A 1 ton refrigeration capacity water cooler cools water steadily from 35 °C to 20 °C. The specific heat of water is 4.18kJ/kg. What is water flow rate in litre/hr?

Question 15

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A piston cyclinder arrangement as shown above, contains air at 250 kPa, 300⁰C. The 50 kg piston has a diameter of 0.1 m and initially pushes against stops. The atmospheric pressure is 100 kPa and temperature is 20⁰C.The cyclinder cools as heat is transferred to the ambient.At what temperature (in ⁰C) does the piston begin to move down?

Question 16

A journal bearing is loaded with a radial load of 30 kN. The journal diameter and length both are 100 mm and it rotates at 1200 rpm. The heat is dissipated from the surface at the rate of 96 J/m²/sec./ °c. The bearing housing is 20 times the projected area. If coefficient of friction is 0.003 and room temperature is 35 °c, then the surface temperature of the bearings is _____ °c.

Question 17

A bar of 3m length, 30 mm breadth, and 20 mm thickness is subjected to a compressive stress of 50 KN/m². What will be the final change in volume of the bar, if Poisson’s ratio is 0.30 and modulus of rigidity is 90GN/m² ?

Question 18

For a cup drawing, the reduction ratio for first and subsequent draw not to exceed 50% and 10% respectively. For 6 draws, the overall drawing ratio will be?

Question 19

Air at 27 ° and 1 bar is heated at constant volume until the pressure is 5 bar and then cooled at constant pressure back to original temperature. Net decrease in entropy of the process is ______ kJ/kgK.

Question 20

The target date of completion of a project is the length of the critical path. The earliest occurrence of events of the tail node (i) and head node (j) of an activity, i-j, in the critical path are 7 and 10 days respectively. The free float of this activity is ______ days.

Question 21

A hole is to be punched in a 30 mm thick plate having an ultimate shear strength of 4 MPa. If allowable crushing stress in the punch is 8 MPa, the diameter of the smallest - hole which can be punched is equal to ______ mm.

Question 22

A cantilever of length 3m is carrying a point load of 50kN at a distance of 2m from the fixed end. If I= 10⁸ mm⁴ and E= 2 × 10⁵ N/mm² . Find the deflection at the free end.

Question 23

A 5 mm diameter and 4 m length steel wire is submerged in a fluid at 50^oC. The conductivity and resistivity of wire is 20 W/m-deg and 70 micro-ohm-cm. If 600 amperes electric current passes through it and conductance at wire surface is 4 kW/m²-deg, then maximum temperature of the wire is

Question 24

Ratio of the buckling strength of the hollow steel column to that of solid square column of the same material, same cross section area, same length. The ratio of outer to inner diameter of hollow column is 2

Question 25

A machine of 100 kg mass is supported on four springs, each of stiffness 200 N/mm. Machine has an unbalanced rotating force of 250 N at speed of 1800 rpm. Taking the damping ratio equal to 0.2, the transmissibilitng ratio is