GATE 2026 CH – Previous Year Questions with Solutions
All 65 questions of GATE 2026 CH with answers and explanations. Read each question, then practise it by topic or as a full paper.
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- Question 1 – "He often the numbers. False claims are not going to help. Honesty trust", said the manager. Choose the option with the correct order of words to fill…
- Question 2 – In the sequence of tiles shown below, the missing tile indicated by the question mark should be
- Question 3 – A school has 100 students distributed among 1st to 10th standards. Based on this, which one of the following statements is always correct?
- Question 4 – How many 3-digit numbers can be formed using three distinct single digit prime numbers?
- Question 5 – In a group of students, 10 students like Mathematics, 12 students like English, 4 students like both Mathematics and English, and 6 students like…
- Question 6 – Charity : P :: Retaliation : Q Choose the appropriate pair of words P and Q that fit the analogy.
- Question 7 – A paper shown in Panel I is folded along the dashed lines (- - -) to construct a cube. The shaded regions shown in Panel I appear on the outer surface…
- Question 8 – Consider the cube shown below with its 8 corners labelled a, b, c, d, e, f, g, and h. The figure is representative. All corners are to be colored such…
- Question 9 – Four hills H1, H2, H3, and H4 are present in an area. The following observations are made about them: i. Neither H2 nor H3 is the easternmost hill.…
- Question 10 – As shown in the figure, circle C 1 with center O 1 and radius r 1 touches the square VWXY at points P and Q while circle C 2 with center O 2 and…
- Question 11 – Which one of the following is NOT a type of chain conveyor?
- Question 12 – In the P&ID shown below, which one of the following is the function of PAH in the process?
- Question 13 – A body is placed inside a perfectly black enclosure and is allowed to reach thermal equilibrium. According to the Kirchhoff's identity, which one of…
- Question 14 – Which one of the following ratios does Grashof number represent?
- Question 15 – Consider a closed system of one mole of an ideal gas undergoing a polytropic process. The process follows PVn = constant, where P is the pressure, V…
- Question 16 – According to the phase rule, which one of the following is the number of degrees of freedom for pure water at its triple point?
- Question 17 – An irreversible chemical reaction occurs on a porous catalyst. All the pores are of same size. In strong pore diffusion regime, the observed…
- Question 18 – In a traditional continuous Kraft (Sulfate) pulping process, consider the following major steps: Bleaching (BL), Chipping (CH), Debarking (DE),…
- Question 19 – For an irreversible reaction containing inerts in the feed, single-pass conversion in a reactor is 70%. Which one of the following statements is…
- Question 20 – A binary mixture of butane and butadiene is to be separated in an extractive distillation using furfural. Furfural lowers the activity of butadiene…
- Question 21 – A two-dimensional temperature profile is given as T = 2x2 + 3xy + y2. If i and j are the unit vectors along x and y directions, respectively, which…
- Question 22 – Which one of the following is the value of x 0 ex - x - 1 x - 1 ?
- Question 23 – Which one of the following is the pair of eigenvalues of the matrix bmatrix -3 & 4 \\ 4 & 3 bmatrix ?
- Question 24 – Which one of the following is produced by catalytic reforming of straight run gasoline and naphtha?
- Question 25 – A process exhibits an inverse response to a step input. Which of the following statements is/are necessarily TRUE about the process?
- Question 26 – Urea has its major use as a solid fertilizer for nitrogen fixation. Which of the following is/are other application(s) of urea?
- Question 27 – Which of the following statements regarding the heat of reaction is/are CORRECT?
- Question 28 – In which of the following condition(s), Bernoulli's equation is applicable?
- Question 29 – Which of the following methods for calculating profitability does/do NOT consider the time value of money?
- Question 30 – Consider two successive screen sizes in the Tyler standard screen scale, viz. 150 meshes per inch and 200 meshes per inch. Their linear sizes of the…
- Question 31 – Consider a homogeneous gas phase reaction, A + 2B 2C + 3D, occurring at constant temperature and pressure in a varying volume batch reactor. The…
- Question 32 – Water is discharged from vertical side of a tank through a circular orifice of diameter 2 cm under laminar flow conditions. The water surface in the…
- Question 33 – Consider a non-reactive binary mixture of two ideal gases A and B in an isothermal horizontal closed tube. Due to the concentration difference at the…
- Question 34 – An experiment is performed by rolling an unbiased die once. Events A and B are defined as follows: Event A: The outcome of the rolled die is a prime…
- Question 35 – Using single step trapezoidal rule, the value of 00.5 (1 + 16x - 20x2)\,dx is (rounded off to two decimal places).
- Question 36 – K value is defined as the ratio of mole fraction of a component in the vapor phase to that in the liquid phase. The K values of propane and iso-butane…
- Question 37 – Consider a flow with the following velocity field V = (x + y)i + (y + z)j + (z + x)k where i, j and k are the unit vectors in the x, y and z…
- Question 38 – Vapor pressure of water at various temperature is given in the table. Temperature (K) 284 289 294 299 310 --- --- --- --- --- --- Vapor pressure (kPa)…
- Question 39 – A volatile organic compound (VOC) is to be adsorbed from air onto a bed of activated carbon. The equilibrium capacity of activated carbon at the feed…
- Question 40 – Consider the following complex numbers z 1 = r 1( 1 + i 1) z 2 = r 2( 2 + i 2) where r 1, r 2 are real numbers, 0 1 2, 0 2 2, and i = -1. If z 1 + z 2…
- Question 41 – Consider the following curve in polar coordinates. r = 2 - 2 Which one of the following is the area enclosed by the curve for 0 2 ?
- Question 42 – Consider the following homogeneous isothermal liquid-phase parallel reactions carried out in three reactor configurations (having identical volumes…
- Question 43 – The reaction rate constants of two reactions follow Arrhenius' law. The activation energies of Reaction 1 and Reaction 2 are E 1 and E 2, respectively…
- Question 44 – A control valve with hyperbolic characteristics has a turndown ratio (ratio of maximum flow to minimum controllable flow) of 50. The flow rate through…
- Question 45 – The gross energy requirement, to reduce a very large feed of coal to such a size that 80% of the product passes through a 100 µm screen, is 13 kWh per…
- Question 46 – In a certain project, 15% of the total investment is the working capital. The minimum acceptable rate of return is 4.95% and the period of evaluation…
- Question 47 – A continuous distillation column is used to separate an equimolar mixture of diethylamine (DEA) and methanol. The feed enters the column as saturated…
- Question 48 – A gas stream with 2.01 mol % ammonia is to be scrubbed in a counter-current isothermal packed bed absorber using pure water to reduce its…
- Question 49 – Laboratory filtration is conducted at constant pressure drop of 200 kPa on a slurry of CaCO 3 in water at room temperature. The time taken to collect…
- Question 50 – Consider three identical non-interacting first order processes in series, each having unit gain and a time constant of 2 min. Tuning of proportional…
- Question 51 – A thermometer initially at a steady temperature of 30 °C is inserted in a water bath maintained at 90 °C. The initial rate of temperature rise of the…
- Question 52 – In a double pipe cocurrent heat exchanger, operating at steady state, oil (specific heat capacity = 2100 J kg-1 °C-1) entering at 7 kg s-1 at 100 °C…
- Question 53 – A pipe with outer diameter of 0.02 m, carries hot water. The temperature at the outer surface of the pipe is 70 °C. This pipe is covered with two…
- Question 54 – Methanol is formed by the following gas phase homogeneous reaction: CO (g) + 2H 2 (g) ⇋ CH 3OH (g) The standard Gibbs free energies of formation at…
- Question 55 – A first-order homogeneous liquid-phase reaction (A→B) occurs in an adiabatic, ideal mixed flow reactor operating at steady state. The volumetric flow…
- Question 56 – A first-order homogeneous liquid-phase reaction (A→B) occurs in a non-ideal isothermal reactor operating at steady state. The variance (2) of…
- Question 57 – A feed containing 10 mol % propylene, 15 mol % ammonia and rest air is charged into a reactor to produce acrylonitrile (C 3H 3N) according to the…
- Question 58 – A gas mixture of 50 wt. % argon and 50 wt. % helium flowing through a horizontal tube of uniform diameter at a rate of 1 kg s-1 is heated from 300 K…
- Question 59 – When a cylindrical capillary glass tube, open at both ends, is vertically inserted in a pool of water, the water level in the tube rises to 7 cm…
- Question 60 – Consider a two-dimensional, steady, laminar flow of an incompressible fluid with zero pressure gradient, over a thin horizontal flat plate of length 2…
- Question 61 – The flooding velocity curves for two different structured packings are shown in the figure. The ratio of mass velocities of liquid (G x) to that of…
- Question 62 – Consider a differential equation: x2d2ydx2 + 3xdydx - 3y = 0 y = 3, dydx = -5 at x = 1 The value of y at x = 2 is (rounded off to two decimal places).
- Question 63 – The data given in the table are fitted to the equation y = mx using the method of least squares. The value of m is (rounded off to one decimal place).…
- Question 64 – Cyclohexane (C 6H 12) is produced from benzene (C 6H 6) and hydrogen (H 2) according to the following reaction. C 6H 6 + 3H 2 ⟶ C 6H 12 Consider the…
- Question 65 – The velocity profile for a fully developed laminar flow of an incompressible Newtonian fluid, at steady state, through a horizontal infinitely wide…