List of top Questions asked in GATE PI

A straight turning operation is carried out at the feed rate of 100 mm/min using a single point cutting tool with signature 8 – 8 – 5 – 5 – 7 – 25 – 0 (ASA). The spindle speed is 1600 rpm. The roughness, in μm, of the machined surface in terms of peak-to-valley height is ................. (round off to 2 decimal places).
An arc welding operation is performed at 25 V and 200 A at welding speed of 2 mm/s. The heat used for melting is 80% of the total heat generated. The unit melting energy of the metal to be joined is 10 J/mm$^3$. The volume of the weld metal produced per unit time, in mm$^3$/s, is ................. (in integer).
Water flows through a pipe of diameter 0.02 m. The Reynolds number of the flow is 1000. The pipe is heated from outside with a uniform heat flux. The flow and heat transfer in the pipe are steady and fully developed. The thermal conductivity of water is 0.66 W/(m-K). The convective heat transfer coefficient, in W/(m$^2$-K), is ................. (round off to 2 decimal places).
The work sampling study, with 100 observations, revealed 25% idle time of a worker. The number of observations required for ±10% accuracy and 95.45% confidence level is ................. (in integer).
A system has 10 essential components. Each component has an exponential time-to-failure distribution with constant failure rate of 0.04 per 4000 hours. The mean-time-to-failure, in hours, of the system is .................
As per the Fe-C phase diagram, the microstructure of plain carbon steel with 0.4 wt.% carbon at room temperature contains
The most appropriate process for manufacturing of plastic chair is
The following equation is solved using Newton-Raphson method \[ x^5 - 15 = 0 \] with initial value \(x_0 = 1.0\). The value of first approximation \(x_1\) is ................. (round off to 2 decimal places).
The total number of nonconformities is 420 from 30 samples. The size of each sample is 100. The lower control limit for the control chart for number of nonconformities is ................. (round off to 2 decimal places).
A metal rod of diameter 14 mm is subjected to a tensile test. After the test, its cross-sectional diameter at the fractured end is 12 mm. The ductility, in %, is ................. (round off to 2 decimal places).
Two cards are drawn one after the other from a regular deck of 52 playing cards without replacement. The probability that the drawn cards are of different suits is
A solid circular disk of 0.025 m thickness is used as a flywheel. The density of the disk material is 7800 kg/m³ and the mass moment of inertia of the disk about its center is 4.36 kg·m². The radius, in m, of the disk is ................. (round off to 2 decimal places).
The standard time for completing a job on a machine is 10 minutes. Number of machines available is 5, each machine is available for 300 hours/month, and average machine utilization is 80%. The maximum number of jobs that can be produced in a month is ................. (in integer).
Under steady state conditions, superheated steam enters the turbine with enthalpy, $h_1 = 3200$ kJ/kg and wet steam leaves the turbine at pressure $p_2 = 0.1$ bar. The heat loss is 100 kJ/kg and work output is 1000 kJ/kg. Kinetic and potential energies for inflow and outflow are neglected. At pressure 0.1 bar, the enthalpy of saturated liquid is 200 kJ/kg and the enthalpy of vaporization is 2400 kJ/kg. The dryness fraction of the steam at the exit of the turbine is ................. (round off to 2 decimal places).
A copper rod of 200 mm diameter and 400 mm length is extruded to the final diameter of 100 mm. The extrusion ratio is
A thin cylinder has length $L$, diameter $d$, and thickness $t$. It is made of a material with modulus of elasticity $E$ and Poisson’s ratio $\mu$. When the cylinder is subjected to an internal pressure $P$, the change in length is
Creep of mild steel at elevated temperature involves
Number of minimum control points required to generate a quadratic B-Spline curve is
The Euler’s method is used to solve \[ \frac{dy}{dx} = x^3 y - 4, y(0) = 1 \] The step size is 0.1. The approximate value of \(y(0.1)\) is ................. (round off to 2 decimal places).
Two plane parallel surfaces exchange heat by thermal radiation. A radiation shield is placed in between at equal distance from the two surfaces to reduce heat transfer. All surfaces are black with infinite length and width. The ratio of heat transfer rate between surfaces with and without radiation shield is
As per the ANSI marking system, a grinding wheel with alumina as abrasive is designated as 51 A 36 K 5 V 23. Here, K indicates that
In NC machine, the function of interpolator is to
Vacuum in the machining zone is an essential requirement for
The qualitative method of forecasting amongst the given options is
The coefficient of \(x^4\) in the polynomial \((x - 1)^3(x - 2)^3\) is equal to .......................