GATE 2025 CH – Previous Year Questions with Solutions
All 65 questions of GATE 2025 CH with answers and explanations. Read each question, then practise it by topic or as a full paper.
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- Question 1 – Is there any good show television tonight? Select the most appropriate option to complete the above sentence.
- Question 2 – As the police officer was found guilty of embezzlement, he was dismissed from the service in accordance with the Service Rules. Select the most…
- Question 3 – The sum of the following infinite series is: 11! + 12! + 13! + 14! + 15! +
- Question 4 – A thin wire is used to construct all the edges of a cube of 1 m side by bending, cutting and soldering the wire. If the wire is 12 m long, what is the…
- Question 5 – The figures I, II and III are parts of a sequence. Which one of the following options comes next in the sequence at IV?
- Question 6 – "Why do they pull down and do away with crooked streets, I wonder, which are my delight, and hurt no man living? Every day the wealthier nations are…
- Question 7 – Rohit goes to a restaurant for lunch at about 1 PM. When he enters the restaurant, he notices that the hour and minute hands on the wall clock are…
- Question 8 – A color model is shown in the figure with color codes: Yellow (Y), Magenta (M), Cyan (Cy), Red (R), Blue (Bl), Green (G), and Black (K). Which one of…
- Question 9 – A circle with center at (x, y) = (0.5, 0) and radius = 0.5 intersects with another circle with center at (x, y) = (1, 1) and radius = 1 at two points.…
- Question 10 – An object is said to have an n-fold rotational symmetry if the object, rotated by an angle of 2n, is identical to the original. Which one of the…
- Question 11 – To manufacture paper from (i), the (ii) must be freed from the binding matrix of (iii) in the pulping step. Which one of the following is the CORRECT…
- Question 12 – Consider a Cartesian coordinate system defined over a 3-dimensional vector space with orthogonal unit basis vectors i, j and k. Let vector a = 2i +…
- Question 13 – Consider two complex numbers z 1 = 1 - i and z 2 = i. The argument of z 1 z 2 is
- Question 14 – A box contains 3 identical green balls and 7 identical blue balls. Two balls are randomly drawn without replacement from the box. The probability of…
- Question 15 – The number of independent intensive variables that need to be specified to determine the thermodynamic state of a ternary mixture at…
- Question 16 – The boundary of a system does not allow exchange of either mass or energy (in the form of heat and/or work) with the surroundings. The system is…
- Question 17 – In industrial heat exchanger design, the overall heat transfer coefficient U is estimated from the equation 1U = 1h i + 1h o where h i and h o are the…
- Question 18 – The sum of the components of the force due to pressure and shear at the solid-fluid boundary of a solid body in the direction normal to the flow is
- Question 19 – Choose the CORRECT option for pathlines, streaklines and streamlines for a STEADY flow field.
- Question 20 – Choose the CORRECT ordering of the diameter d of the different types of pores in a solid catalyst.
- Question 21 – Schmidt number is defined as
- Question 22 – If k is the mass transfer coefficient and D v is the molecular diffusivity, which one of the following statements is NOT CORRECT with respect to mass…
- Question 23 – Choose the CORRECT statement that describes the dependence of the variance ( 2) of the residence time distribution (RTD) with respect to the number of…
- Question 24 – The vortex shedding meter is primarily used for measuring
- Question 25 – Choose the transfer function that best fits the output response to a unit step input change shown in the figure
- Question 26 – The capital cost (CC) of an industrial equipment varies with its capacity (S) as CC S. The rule-of-thumb value of the exponent is
- Question 27 – In the production of polyvinyl chloride (PVC) from ethylene and chlorine, the sequential order of reactions is
- Question 28 – In the CONTACT PROCESS for manufacturing sulphuric acid, the reaction converting SO 2 to SO 3 is
- Question 29 – Choose the option that correctly matches the items in Group 1 with those in Group 2. Group 1 Group 2 --- --- (P) Coking (I) Prolonged exposure of…
- Question 30 – Which of the following statements regarding multiple effect evaporators is/are TRUE?
- Question 31 – Consider an enzymatic reaction that follows Michaelis-Menten kinetics. Let K M, S, and V max denote the Michaelis constant, substrate concentration,…
- Question 32 – The following data is given for a ternary ABC gas mixture at 12 MPa and 308 K: Component i A B C --- --- --- --- y i 0.55 0.20 0.25 i 0.75 0.80 0.95 y…
- Question 33 – Ideal nonreacting gases A and B are contained inside a perfectly insulated chamber, separated by a thin partition, as shown in the figure. The…
- Question 34 – Oil is extracted from mustard seeds having 20 wt% oil and 80 wt% solids, using hexane as a solvent. After extraction, the hexane-free residual cake…
- Question 35 – The residence-time distribution (RTD) function of a reactor (in min-1) is E(t) = cases 1 - 2t, & t 0.5 min \\ 0, & t > 0.5 min cases The mean…
- Question 36 – Consider a Cartesian coordinate system with orthogonal unit basis vectors i, j defined over a domain: x, y [0, 1]. Choose the condition for which the…
- Question 37 – A probability distribution function is given as p(x) = cases 1a, & x (0, a) \\ 0, & otherwise cases where a is a positive constant. For a function…
- Question 38 – A hot plate is placed in contact with a cold plate of a different thermal conductivity as shown in the figure. The initial temperature (at time t = 0)…
- Question 39 – The first-order irreversible liquid phase reaction A B occurs inside a constant volume (V) isothermal CSTR with the initial steady state conditions…
- Question 40 – 500 mg of a dry adsorbent is added to a beaker containing 100 mL solution of concentration 100 mg phenol/(L solution). The adsorbent is separated out…
- Question 41 – A catalyst particle is modeled as a symmetrical double cone solid as shown in the figure. For each conical sub-part, the radius of the base is r and…
- Question 42 – A zero-order gas phase reaction A B with rate (-r A) = k = 100 mol/(L min) is carried out in a mixed flow reactor of volume 1 L. Pure A is fed to the…
- Question 43 – For a steady state, fully developed laminar flow of a Newtonian fluid through a cylindrical pipe at a constant volumetric flow rate, which of the…
- Question 44 – Consider the differential equation dydx + yx = 0 Choose the CORRECT option(s) for the solution y.
- Question 45 – Consider the matrix A = bmatrix 2 & 3 \\ 1 & 2 bmatrix The eigenvalues of the matrix are 0.27 and (rounded off to 2 decimal places).
- Question 46 – The Newton-Raphson method is used to find the root of f(x) x2 - x - 1 = 0. Starting with an initial guess x(0) = 1, the second iterate x(2) is…
- Question 47 – Consider moist air with absolute humidity of 0.02 (kg moisture)/(kg dry air) at 1 bar pressure. The vapour pressure of water is given by the equation…
- Question 48 – An ideal monoatomic gas is contained inside a cylinder-piston assembly connected to a Hookean spring as shown in the figure. The piston is…
- Question 49 – A leaf filter is operated at 1 atm (gauge). The volume of filtrate collected (V in m3) is related with the volumetric flow rate of the filtrate (q in…
- Question 50 – An adiabatic pump of efficiency 40% is used to increase the water pressure from 200 kPa to 600 kPa. The flow rate of water is 600 L/min. The specific…
- Question 51 – Water flowing at 70 kg/min is heated from 25 °C to 65 °C in a counter-flow double pipe heat exchanger using hot oil. The oil enters at 110 °C and…
- Question 52 – Consider laminar flow of water over a wide flat plate maintained at a uniform temperature of 50 °C as shown in the figure. The freestream velocity and…
- Question 53 – An electrical wire of 2 mm diameter and 5 m length is insulated with a plastic layer of thickness 2 mm and thermal conductivity k = 0.1 W/(m K). It is…
- Question 54 – A binary AB liquid mixture containing 30 mol% A is subjected to differential (Rayleigh) distillation at atmospheric pressure in order to recover 60…
- Question 55 – Gas containing 0.8 mol% component A is to be scrubbed with pure water in a packed bed column to reduce the concentration of A to 0.1 mol% in the exit…
- Question 56 – Solute A is absorbed from a gas into water in a packed bed operating at steady state. The absorber operating pressure and temperature are 1 atm and…
- Question 57 – Components A and B form an azeotrope. The saturation vapour pressures of A and B at the boiling temperature of the azeotrope are 87 kPa and 72.7 kPa,…
- Question 58 – The reaction A products with reaction rate, (-r A) = kC A3, occurs in an isothermal PFR operating at steady state. The conversion (X) at two axial…
- Question 59 – The catalytic gas phase reaction A products is carried out in an isothermal batch reactor of 10 L volume using 0.1 kg of a solid catalyst. The…
- Question 60 – Consider a process with transfer function G p = 2e-s(5s + 1)2 A first-order plus dead time (FOPDT) model is to be fitted to the unit step process…
- Question 61 – Methanol is produced by the reversible, gas-phase hydrogenation of carbon monoxide as CO + 2H 2 CH 3OH CO and H 2 are charged to a reactor and the…
- Question 62 – The block diagram of a series cascade control system (with time in minutes) is shown in the figure. For I = 8 min and K cs = 1, the maximum value of K…
- Question 63 – It is proposed to install thermal insulation in a residence to save on the summer-monsoon season air-conditioning costs. The estimated yearly saving…
- Question 64 – Consider the flowsheet in the figure for manufacturing C via the reaction A + B C in an isothermal CSTR. The split in the separator is perfect so that…
- Question 65 – A wet solid of 100 kg containing 30 wt% moisture is to be dried to 2 wt% moisture in a tray dryer. The critical moisture content is 10 wt% and the…