GATE 2025 Unofficial Answer Key (Available) LIVE Updates: Memory-based questions PDF Feb 1 and 2

04 40 PM IST - 02 Mar'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q9

In a cyclone separator of radius 25 cm, a particle is travelling with a gas stream at velocity of 18 m/s. The ratio of centrifugal force to the gravitational force acting on the particle is _______ (rounded off to 2 decimal places).

Consider acceleration due to gravity (g) as 9.8 m/s²

06 45 AM IST - 02 Mar'25

GATE 2025 Unofficial Answer Key: Upcoming Events

10 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q12

An irrigation pump is used to draw water from a pond. One end of a 5.05 cm diameter hose pipe is connected to the outlet of the pump at 1.02 m below the surface level, and just after the pump, the static gauge pressure and flow rate of the water are 50 kPa and 8 kg/s, respectively. The pumped water is discharged at the ground level through a nozzle. Assume that the flow through the hose pipe and nozzle is steady and laminar, and frictional and viscous losses are negligible. The density of water is 1000 kg/m³ and the acceleration due to gravity is 9.81 m/s² . If the static pressure at the nose/exit of the nozzle just reduces to atmospheric pressure then the nose diameter (in cm) of the nozzle is ___________ . (Rounded off to 2 decimal places)

09 45 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q11

A metallic cylindrical pressure vessel, used to store compressed air in a plant, has 1 m mean radius and 4 mm wall thickness. The maximum allowable normal and shear stresses in the cylindrical portion of the vessel are 100 MPa and 40 MPa, respectively. Considering only these data in the design, the maximum allowable internal gauge pressure (in MPa) of the compressed air is ___________ . (Rounded off to 2 decimal places)

09 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q10

Mild steel plates are welded to make butt joints by arc welding with 85% heat transfer efficiency ignoring other losses. The first weld joint is made by selecting arc voltage of 30 V and current of 180 A with a welding speed of 6 mm/s. Using identical plates, a second weld joint is made with the same arc voltage and a welding speed of 8 mm/s. If both the welds have the same heat input, then the welding current (in A) for the second weld joint is _________ . (Answer in integer)

09 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q9

In a single pass cold rolling operation, a flat plate is reduced to a thickness of 3 mm. In this operation, two rolls of diameter 400 mm each are rotating in opposite direction at 300 RPM, and the elastic deflection of these rolls is negligible. The angle of bite is 10º. If the neutral point is present at an angle of 7º from the exit side, then the thickness of the plate (in mm) at the neutral point is _________ . (Rounded off to 1 decimal place)

08 40 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q8

The following data are given in relation to turning operation of a cylindrical workpiece.

Diameter of the workpiece = 160 mm, length of the workpiece = 190 mm, cutting velocity = 80π m/min, and tool feed = 0.2 mm/rev. 

Assuming the approach and the overrun of the tool to be 5 mm each, the machining time (in minutes) is _________ . (Answer in integer)

08 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q7

The pitch of a metric screw thread is calculated from pitch circle diameter measurement through two-wire method. If the thread is single-start with calculated pitch of 1.4 mm then the diameter (in mm) of the best-wire is __________ . (Rounded off to 2 decimal places)

08 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q6

During orthogonal turning, the cutting speed, feed and depth of cut are set as 2 m/s, 0.2 mm/rev and 2 mm, respectively. The specific cutting energy (neglecting the effect of feed force on the total cutting power) is 2 J/mm³ . The main cutting force (in N) is __________ . (Answer in integer)

07 40 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q5

Electro-chemical machining is performed on a flat copper workpiece. If the material removal rate is 2 cm³ /min throughout the process, then the required current (in A) is _________ . (Rounded off to 1 decimal place)

Copper properties: Melting point = 1085 ºC, density = 9 g/cm³ , gram atomic weight = 63, and valency of dissolution = 2

Faraday’s constant = 96500 C

Stefan-Boltzmann constant = 5.67 × 10⁻⁸ W/m² -K ⁴

07 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q4

A repairable machine operated for 2400 hours in a year and for that year the machine broke down 8 times. The mean time to repair including waiting time is found to be 20 hours for that year.

If the mean time to repair including waiting time could have been reduced to 10 hours for that year, then the improvement in the availability of that machine would be ___________ %. (Rounded off to 2 decimal places)

07 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q3

In a time study, the average time taken for packaging a product in a warehouse by a worker with 120% performance rating is observed as 9 minutes. Assuming an allowance of 10% of the standard time, the standard time (in minutes) for packaging is _________ . (Answer in integer)

06 40 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q2

An assembly line consists of three work stations (S1, S2 and S3) in series to assemble a toy. The times required to perform tasks at these stations are 6, 4 and T minutes, respectively. If the efficiency of the assembly line in the steady state is 75%, then the maximum value of T (in minutes) is ____________. (Answer in integer)

06 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's PI Q1

A company orders an item using the classical economic order quantity formula. If the ordering cost per order is increased by 20% and the demand per unit time is also increased by 20%, then the time between orders increases (in %) by ________ . (Answer in integer).

06 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q13

The pH of a solution containing 0.1M of acetic acid and 0.05 M of sodium acetate is ________ (rounded off to 2 decimal places).

The pK_a value of ionization of acetic acid is 4.76.

05 40 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q12

The ionic strength of a solution containing 0.01M of CaCl₂ and 0.001M of Na₂SO₄ is ________ M (rounded off to 3 decimal places).

05 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q11

The concentration of Ozone corresponding to a mixing ratio of 120 ppbv at pressure of 1 atmosphere and temperature of 25°C is ________ µg/m³ (rounded off to 1 decimal place).

Atomic weight of oxygen = 16; R= 8.314 J/K-g.mole.

05 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q10

An industry discharges 2 million liters per day (MLD) of wastewater with a temperature of 45℃ and a pH of 2, whereas the neighboring industry produces 3 MLD of wastewater with a temperature of 30℃ and pH of 8. If both the wastewaters are mixed and carried through a pipeline, then the resultant pH of mixed wastewater is ________ (rounded off to 2 decimal places).

Neglect buffering capacity of the system and the temperature effect on pH.

04 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q8

Two sources of noise, adjacent to each other in a room, have sound pressure levels of 30 and 40 decibel (dB). The combined sound pressure level in the room is _______ dB (rounded off to 2 decimal places).

Use reference sound pressure as 20 µPa.

04 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q7

An industrial stack emits 100 g/s of CO at an effective height of ‘H’, where the wind speed is 5 m/s. At 3 km distance downwind, the values of dispersion coefficient in ydirection and z-direction are 50 m and 25 m, respectively. The CO concentration at the centerline of the plume at 3 km distance downwind is _______ mg/m³ (rounded off to 2 decimal places)?

Use Gaussian plume model and value of π = 3.14. Neglect reactions and the ground effect of plume in the calculations.

03 40 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q6

Two hypothetical organic waste streams A and B are mixed prior to the composting process. Waste-A has 2.16% of C and 1.20% of N. Waste-B has 19.10% of C and 0.14% of N. The quantity of Waste-B that should be mixed with per kg of Waste-A to achieve the desired C:N ratio of 25 is _______kg (rounded off to 2 decimal places).

Assume both the waste streams are completely dry.

03 20 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q5

Food waste, paper waste and plastic waste have typical densities of 280 kg/m³ , 80 kg/m³ , and 50 kg/m³ , respectively. The mixed waste is composed of 70% food waste, 20% paper waste and 10% plastic waste. The density of the mixed waste is _______ kg/m³ (rounded off to 2 decimal places).

Neglect compaction effect.

03 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q4

For a biodegradable waste with a chemical formula C₅₀H₁₀₀O₄₀N, the maximum theoretical methane production per ton of waste is _______ kg (rounded off to 2 decimal places).

Assume 100% anaerobic conversion. Atomic weights of C-12; H-1; O-16; N-14

02 45 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q3

In a region, total annual consumption of gasoline is 30.6 million tons. The land required for growing sugarcane to produce enough bioethanol to replace the gasoline completely is _______ km² (an integer value).

Ethanol energy equivalent is 67% of gasoline, gasoline density is 850 kg/m³ , yield of bioethanol produced from sugarcane per hectare of land is 3750 L, and 1 km² = 100 hectares

02 30 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q2

A person consumes 2.5 liters of water per day. The water quality test indicated that the supplied water has a Pb concentration of 0.6 mg/L. If the weight of the person is 75 kg, the exposure level for Pb for this person from this drinking water source is _______mg/kg/day (rounded off to 2 decimal places).

02 15 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's ES Q1

Initially a bottle contained 400 g of ethanol. Half of ethanol was used by a student for preparing the stock solution in an environmental chemistry laboratory just before summer vacation of 90 days. After completing the procedure, the student left the bottle uncorked. If the unsealed bottle losses ethanol at a rate of 0.5 g/day, the ethanol that will be left in the bottle at the end of the summer vacation is _______ g (an integer value).

02 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q7

A chemical rocket with an ideally expanded flow through the nozzle produces 5 × 10⁶ N thrust at sea level. The specific impulse of the rocket is 200 s and acceleration due to gravity at the sea level is 9.8 m/s² . The propellent mass flow rate out of the rocket nozzle is _________ kg/s (rounded off to the nearest integer).

01 45 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q6

The cross section of a thin-walled beam with uniform wall thickness t, shown in the figure, is subjected to a bending moment M_x = 10 Nm. If h = 1 m and t = 0.001 m, the magnitude of maximum normal stress in the cross section is _________N/m² (answer in integer).

01 30 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q5

For an aircraft moving at 4 km altitude above mean sea level at a Mach number of 0.2, the ratio of equivalent air speed to true air speed is _______ (rounded off to 2 decimal places).

The density of air at mean sea level is 1.225 kg/m³ and at 4 km altitude is 0.819 kg/m³ .

01 15 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q4

Consider an artificial satellite moving around the Moon in an elliptic orbit. The altitude of the satellite from the Moon’s surface at the perigee is 25 km and that at the apogee is 134 km. Assume the Moon to be spherical with a radius of 1737 km. The trajectory is considered with reference to a coordinate system fixed to the center of mass of the Moon. The ratio of the speed of the satellite at the perigee to that at the apogee is ___________ (rounded off to 2 decimal places).

01 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q3

For a general aviation airplane, one of the complex conjugate pair of eigenvalues for longitudinal dynamics is given by −0.039 ± 0.0567 i (in SI units). If the system is disturbed to excite only this mode, the time taken for the amplitude of response to become half in magnitude is _______ s (rounded off to 1 decimal place).

12 45 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q2

An airplane of mass 1000 kg is in a steady level flight with a speed of 50 m/s. The wing has an elliptic planform with a span of 20 m and planform area 31.4 m² . Assuming the density of air at that altitude to be 1 kg/m³ and acceleration due to gravity to be 10 m/s² , the induced drag on the wing is _________ N (rounded off to 1 decimal place).

12 30 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Day 2 Shift 2 Exam Ends

Day 2 shift 2 GATE 2025 exam ends. Candidates are advised to stay connected with this live blog to get all the latest update on the subject-wise unofficial answer key download link. 

12 15 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's AE Q1

It is desired to estimate the aerodynamic drag, D, on a car traveling at a speed of 30 m/s. A one-third scale model of the car is tested in a wind-tunnel following the principles of dynamic similarity. The drag on the scaled model is measured to be D_m. The ratio D/D_m is _________ (rounded off to 1 decimal place).

12 00 PM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q8

Given a dataset with K binary-valued attributes (where K > 2) for a two-class classification task, the number of parameters to be estimated for learning a naïve Bayes classifier is____

11 45 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q7

Consider the following tree traversals on a full binary tree:

(i) Preorder

(ii) Inorder

(iii) Postorder

Which of the following traversal options is/are sufficient to uniquely reconstruct the full binary tree?

A. (i) and (ii)

B. (ii) and (iii)

C. (i) and (iii)

D. (ii) only

11 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q6

The sample average of 50 data points is 40. The updated sample average after including a new data point taking the value of 142 is ______.

11 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q5

Consider the following sorting algorithms:

(i) Bubble sort

(ii) Insertion sort

(iii) Selection sort

Which ONE among the following choices of sorting algorithms sorts the numbers in the array [4, 3, 2, 1, 5] in increasing order after exactly two passes over the array?

A. (i) only

B. (iii) only

C. (i) and (iii) only

D. (ii) and (iii) only

11 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q4

Let X be a random variable uniformly distributed in the interval [1, 3] and Y be a random variable uniformly distributed in the interval [2, 4]. If X and Y are independent of each other, the probability P(X ≥ Y) is ______ (rounded off to three decimal places).

10 45 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q3

Consider two events T and S. Let

10 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q2

Details of ten international cricket games between two teams “Green” and “Blue” are given in Table C. This table consists of matches played on different pitches, across formats along with their winners. The attribute Pitch can take one of two values: spin-friendly (represented as

10 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's DA Q1

Two fair coins are tossed independently. X is a random variable that takes a value of 1 if both tosses are heads and 0 otherwise. Y is a random variable that takes a value of 1 if at least one of the tosses is heads and 0 otherwise. The value of the covariance of X and Y is ______ (rounded off to three decimal places).

10 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of EE

09 45 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of AR

09 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Day 2 Shift 1 Exam Starts

GATE 2025 February 2 shift 1 exam has started, which will be ended at 12.30 PM. After that the candidates can check out the shift 1 subject-wise unofficial answer key here. 

09 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of PE

09 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of ME

08 45 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of IN

08 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of TF

08 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of MT

08 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of NM

07 45 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of CS

07 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of MA

07 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Year's Cutoff Trend of AG

07 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q9

The non-dissociative adsorption of a gas on a given surface at a fixed temperature follows Langmuir isotherm. The plot(s) which give(s) a straight line is (are) [Given: V = volume of the adsorbed gas, P = pressure of the gas]

A. 1/V versus 1/P

B. P/V versus P

C. V versus P

D. V versus 1/P

06 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q8

¹H NMR spectrum of a mixture containing CH₃Br (x mol) and (CH₃)₃CBr (y mol) shows two singlets at 2.7 ppm and 1.8 ppm, with the relative ratio of 3:1 (integration value), respectively. The value of x/y is ____.

06 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q7

The partial vapor pressure of 0.1 molal solution of B in liquid A is 60 kPa at 300 K. The partial vapor pressure (in kPa) of a solution containing B with mole fraction of 0.1 in liquid A at 300 K is ___. (Assume the solute B obeys Henry’s law. The molar mass of A is 80 g mol^-1 .) (rounded off to three decimal places)

06 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q6

In the EPR spectrum of an aqueous solution of VOSO₄ at room temperature, the total number of hyperfine splitting signals is

A. 3

B. 7

C. 5

D. 8

05 45 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q5

Among the following, the NMR active nucleus(nuclei) is (are)-

A. ¹²C

B. ¹⁹F

C. ²H

D. ¹⁶O

05 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q4

The complex(es) that exhibit(s) optical isomerism is (are)-

A. [Fe(acac)₃]

B. cis-[Co(en)₂Cl₂] ⁺

C. trans-[Co(en)₂Cl₂] ⁺

D. [Co(en)₃] ³⁺

05 15 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q3

The turnover frequency (in h ⁻¹ ) of a reaction where 5 mol% of a catalyst is required for 90% conversion in 3 h is ____. (rounded off to the nearest integer)

05 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q2

In thermogravimetric analysis, 12.45 mg of CuSO₄·5H₂O was subjected to heating under N₂ atmosphere. At a particular temperature, there was a weight loss of 3.6 mg. The number of water molecule(s) lost per formula unit is ____. (Given molar mass (in g mol^-1) of H = 1.0, O = 16.0, S = 32.0, and Cu = 63.5) (rounded off to the nearest integer)

04 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ CY Q1

2 mol of a monoatomic ideal gas with initial volume of 5 L and pressure 10 bar undergoes an irreversible adiabatic expansion against a constant final pressure of 1 bar. The final volume (in L) is ______. (Given: R = 8.314 × 10^-2 L bar mol^-1 K ^-1) (rounded off to one decimal place)

04 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ AR Q5

In 2021, a city survey report revealed a sex ratio of 930 with an estimated increase of 2.16% over the next 20 years. In 2041, the total population of the city is projected to be 15,00,000. The estimated female population in the year 2041 will be ____________ (in integer).

03 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ AR Q4

In a one-way single lane traffic stream, the observed average time headway is 2.5 seconds. The traffic flow of the above mentioned lane, in vehicle/hr, is _____________(in integer).

03 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ AR Q3

Labour supply and urban growth are represented in X and Y axis of the Figure below. Curve OP represents the relationship between labour supply and urban growth. The ratios A:A’ and B:B’ are 1:1.2 and 3:1.2, respectively. If 6 units of labour is supplied in B, then the number of units of urban growth in B’ will be _____________ (rounded off to one decimal place).

02 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ AR Q2

The demand of a EcoCity theme park is estimated as P = 1500 − 7.5Q, where P (in Indian Rupees) is the price of a ticket for single entry, and Q (in integer) is the number of tickets sold per hour. The maximum revenue per hour along the demand curve, in Indian Rupees, is _____________(in integer).

02 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ AR Q1

A city with a present population of 1,75,000 is expecting an annual population growth rate of 0.85%. In a traffic assessment study, the trip generation model has been developed as Y = 142 + 0.675X, where Y is the number of daily trips generated within the city and X is the population of the city. The number of daily trips to be generated within the city after 10 years is _____________(in integer).

01 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q11

A 5 kW, 220 V DC shunt motor has 0.5 Ω armature resistance including brushes. The motor draws a no-load current of 3 A. The field current is constant at 1 A. Assuming that the core and rotational losses are constant and independent of the load, the current (in amperes) drawn by the motor while delivering the rated load, for the best possible efficiency, is ________ (rounded off to 2 decimal places).

01 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q10

A single-phase half-controlled bridge converter supplies an inductive load with ripple free load current. The triggering angle of the converter is 60°. The ratio of the rms value of the fundamental component of the input current to the rms value of the total input current of the bridge is _________ (rounded off to 3 decimal places).

12 30 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q9

A single-phase full bridge voltage source inverter (VSI) feeds a purely inductive load. The inverter output voltage is a square wave in 180° conduction mode. The fundamental frequency of the output voltage is 50 Hz. If the DC input voltage of the inverter is 100 V and the value of the load inductance is 20 mH, the peak-topeak load current in amperes is _________ (rounded off to the nearest integer).

12 00 AM IST - 02 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q21

A flat surface of a C60 steel having dimensions of 100 mm (length) × 200 mm (width) is produced by a HSS slab mill cutter. The 8-toothed cutter has 100 mm diameter and 200 mm width. The feed per tooth is 0.1 mm, cutting velocity is 20 m/min and depth of cut is 2 mm. The machining time required to remove the entire stock is _____________ minutes (rounded off to 2 decimal places).

11 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q20

In an arc welding process, the voltage and current are 30 V and 200 A, respectively. The cross-sectional area of the joint is 20 mm2 and the welding speed is 5 mm/s. The heat required to melt the material is 20 J/s. The percentage of heat lost to the surrounding during the welding process is _________ (rounded off to 2 decimal places).

11 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q19

A blanking operation is performed on C20 steel sheet to obtain a circular disc having a diameter of 20 mm and a thickness of 2 mm. An allowance of 0.04 is provided. The punch size used for the operation is ___________ mm (rounded off to 2 decimal places)

10 40 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q18

Aluminium is casted in a cube-shaped mold having dimensions as 20 mm × 20 mm × 20 mm. Another mold of the same mold material is used to cast a sphere of aluminium having a diameter of 20 mm. The pouring temperature for both cases is the same. The ratio of the solidification times of the cube-shaped mold to the spherical mold is ________ (answer in integer).

10 20 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q17

A cutting tool provides a tool life of 60 minutes while machining with the cutting speed of 60 m/min. When the same tool is used for machining the same material, it provides a tool life of 10 minutes for a cutting speed of 100 m/min. If the cutting speed is changed to 80 m/min for the same tool and work material combination, the tool life computed using Taylor’s tool life model is____________ minutes (rounded off to 2 decimal places).

10 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q16

A condenser is used as a heat exchanger in a large steam power plant in which steam is condensed to liquid water. The condenser is a shell and tube heat exchanger which consists of 1 shell and 20,000 tubes. Water flows through each of the tubes at a rate of 1 kg/s with an inlet temperature of 30°C. The steam in the condenser shell condenses at the rate of 430 kg/s at a temperature of 50°C. If the heat of vaporization is 2.326 MJ/kg and specific heat of water is 4 kJ/(kg.K), the effectiveness of the heat exchanger is ________ (rounded off to 3 decimal places).

09 40 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q15

A company orders gears in conditions identical to those considered in the economic order quantity (EOQ) model in inventory control. The annual demand is 8000 gears, the cost per order is 300 rupees, and the holding cost is 12 rupees per month per gear. The company uses an order size that is 25% more than the optimal order quantity determined by the EOQ model. The percentage change in the total cost of ordering and holding inventory from that associated with the optimal order quantity is-

A. 2.5

B. 5

C. 0

D. 12.5

09 20 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q14

A queueing system has one single server workstation that admits an infinitely long queue. The rate of arrival of jobs to the queueing system follows the Poisson distribution with a mean of 5 jobs/hour. The service time of the server is exponentially distributed with a mean of 6 minutes. In steady state operation of the queueing system, the probability that the server is not busy at any point in time is-

A. 0.20

B. 0.17

C. 0.50

D. 0.83

09 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q13

The preparatory functions in Computer Numerical Controlled (CNC) machine programing are denoted by the alphabet-

A. G

B. M

C. P

D. O

08 40 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q12

The most suitable electrode material used for joining low alloy steels using Gas Metal Arc Welding (GMAW) process is-

A. Copper

B. Cadmium 

C. Low Alloy Steel

D. Tungsten

08 20 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q11

The allowance provided to a pattern for easy withdrawal from a sand mold is-

A. Finishing Allowance

B. Shrinkage Allowance

C. Distortion Allowance

D. Shake Allowance

08 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q10

The “Earing” phenomenon in metal forming is associated with-

A. Deep drawing

B. Rolling

C. Extrusion

D. Forging

07 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q9

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

A. Soderberg line

B. Modified Goodman line

C. Gerber line

D. Yield line

07 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q8

A linear spring-mass-dashpot system with a mass of 2 kg is set in motion with viscous damping. If the natural frequency is 15 Hz, and the amplitudes of two successive cycles measured are 7.75 mm and 7.20 mm, the coefficient of viscous damping (in N.s/m) is 

A. 4.41

B. 7.51

C. 2.52

D. 6.11

07 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q7

Which one of the following statements regarding a Rankine cycle is FALSE?

A. Superheating the steam in the boiler increases the cycle efficiency.

B. The pressure at the turbine outlet depends on the condenser temperature.

C. Cycle efficiency increases as condenser pressure decreases.

D. Cycle efficiency increases as boiler pressure decreases.

07 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q6

A furnace can supply heat steadily at 1200 K at a rate of 24000 kJ/min. The maximum amount of power (in kW) that can be produced by using the heat supplied by this furnace in an environment at 300 K is

A. 300

B. 150

C. 18000

D. 0

06 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q5

Four equilateral triangles are used to form a regular closed three-dimensional object by joining along the edges. The angle between any two faces is 

A. 30°

B. 60°

C. 45°

D. 90°

06 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q4

How many combinations of non-null sets A, B, C are possible from the subsets of {2, 3, 5} satisfying the conditions: (i) A is a subset of B, and (ii) B is a subset of C?

A. 28

B. 27

C. 18

D. 19

06 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q3

Take two long dice (rectangular parallelepiped), each having four rectangular faces labelled as 2, 3, 5, and 7. If thrown, the long dice cannot land on the square faces and has 1/4 probability of landing on any of the four rectangular faces. The label on the top face of the dice is the score of the throw. 

If thrown together, what is the probability of getting the sum of the two long dice scores greater than 11? 

A. ⅜

B. ⅛

C. 1/16

D. 3/16

06 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q1

Find the odd one out in the set: {19, 37, 21, 17, 23, 29, 31, 11}

A. 21

B. 29

C. 37

D. 23

06 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ ME Q2

In the following series, identify the number that needs to be changed to form the Fibonacci series. 1, 1, 2, 3, 6, 8, 13, 21,…

A. 8

B. 21

C. 6

D. 13

05 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: GATE EE Expected Marks vs Rank

05 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: GATE CSE Expected Qualifying Cutoff Marks 2025

05 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: GATE Electrical Engineering (EE) Expected Qualifying Cutoff Marks

05 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: GATE Mechanical (ME) Expected Qualifying Cutoff Marks

04 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q8

A 3-phase, 11 kV, 10 MVA synchronous generator is connected to an inductive load of power factor (√3/2) via a lossless line with a per-phase inductive reactance of 5 Ω. The per-phase synchronous reactance of the generator is 30 Ω with negligible armature resistance. If the generator is producing the rated current at the rated voltage, then the power factor at the terminal of the generator is

A. 0.63 lagging

B. 0.87 lagging

C. 0.63 leading

D. 0.87 leading

04 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q7

A single-phase triac based AC voltage controller feeds a series RL load. The input AC supply is 230 V, 50 Hz. The values of R and L are 10 Ω and 18.37 mH, respectively. The minimum triggering angle of the triac to obtain controllable output voltage is 

A. 15°

B. 30°

C. 45°

D. 60°

04 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q6

If the following switching devices have similar power ratings, which one of them is the fastest? 

A. SCR

B. GTO

C. IGBT

D. Power MOSFET

04 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q5

A three phase, 50 Hz, 6 pole induction motor runs at 960 rpm. The stator copper loss, core loss, and the rotational loss of the motor can be neglected. The percentage efficiency of the motor is 

A. 92

B. 94

C. 96

D. 98

03 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q4

A surveyor has to measure the horizontal distance from her position to a distant reference point C. Using her position as the center, a 200 m horizontal line segment is drawn with the two endpoints A and B. Points A, B, and C are not collinear. Each of the angles ∠CAB and ∠CBA are measured as 87.8°. The distance (in m) of the reference point C from her position is nearest to

A. 2603 

B. 2606

C. 2306 

D. 2063

03 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q3

In the given text, the blanks are numbered (i)−(iv). Select the best match for all the blanks.

Following a row (i) the shopkeeper (ii) the price of a frying pan, the cook stood (iii) a row to withdraw cash (iv) the ATM booth.

A. (i) with (ii) over (iii) at (iv) with

B. (i) at (ii) over (iii) over (iv) in

C. (i) with (ii) over (iii) in (iv) at

D. (i) over (ii) with (iii) over (iv) at

03 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q2

A shopkeeper buys shirts from a producer and sells them at 20% profit. A customer has to pay ₹3,186.00 including 18% taxes, per shirt. At what price did the shopkeeper buy each shirt from the producer? 

A. ₹2,500.00 

B. ₹1,975.40

C. ₹2,250.00

D. ₹2,548.80

03 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Previous Years’ EE Q1

The decimal number system uses the characters 0, 1, 2, …, 8, 9, and the octal number system uses the characters 0, 1, 2, …, 6, 7. 

For example, the decimal number 12 ( = 1 × 10¹ + 2 × 10⁰ ) is expressed as 14 ( = 1 × 8¹ + 4 × 8⁰ ) in the octal number system. 

The decimal number 108 in the octal number system is:

A. 168

B. 108

C. 150

D. 154

02 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: When will the official answer key release?

Based on the previous year’s trends, it can be assumed that the GATE official answer key will be released tentatively by February 26, 2025. Till then candidates can check and download the subject-wise unofficial answer key pdf here. 

02 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: When will GATE result release?

As per the notice, the GATE 2025 result will be released on March 19, 2025 on the official website. Post that the candidates who will qualify for the exam, will be able to download the scorecard between March 28 to 31, 2025.

02 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: How to Save Answers?

• Candidates should click on the “Save and Next” option which will be seen on the screen
• If the candidates are not sure about the marked responses then they can choose the “Mark for Review and Next” option

02 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Procedure of Answering a Question

• When answering the MCQs, the candidates should click on the particular option to select
• For deselecting the option, the candidates should click on the option again. Then they can choose the clear response option for deselecting the option
• For the numerical type questions, the candidates need to enter the answer through the virtual keyboard displayed on the screen

01 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Steps to Navigate a Questions

Go through the following steps to navigate the questions.

• Candidates will find a serial-wise question list available on the right side of the screen
• Post that the candidates can directly navigate to the question by clicking the GATE question number
• Now the questions will be displayed on the screen when the question button is clicked

01 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: MN Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 MN exam, can go through the following direct link to appear for the exam.

GATE MN Mock Test Link 2025

01 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: XL Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 XL exam, can go through the following direct link to appear for the exam.

GATE XL Mock Test Link 2025

01 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: XE Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 XE exam, can go through the following direct link to appear for the exam.

GATE XE Mock Test Link 2025

12 45 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: ST Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 ST exam, can go through the following direct link to appear for the exam.

GATE ST Mock Test Link 2025

12 30 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Shift 1 Exam Ends

GATE 2025 February 1 shift 1 exam ends. Soon the unofficial answer keys for the subjects along with the memory-based questions will be available. 

12 15 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: CE2 Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 CE2 exam, can go through the following direct link to appear for the exam.

GATE CE2 Mock Test Link 2025

12 00 PM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: CE1 Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 CE1 exam, can go through the following direct link to appear for the exam.

GATE CE1 Mock Test Link 2025

11 45 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: BT Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 BT exam, can go through the following direct link to appear for the exam.

GATE BT Mock Test Link 2025

11 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: PH Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 PH exam, can go through the following direct link to appear for the exam.

GATE PH Mock Test Link 2025

11 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: CH Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 CH exam, can go through the following direct link to appear for the exam.

GATE CH Mock Test Link 2025

11 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: GG Mock Test Link

Candidates who will be appearing for the February 16 GATE 2025 GG exam, can go through the following direct link to appear for the exam.

GATE GG Mock Test Link 2025

10 45 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: EY Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 EY exam, can go through the following direct link to appear for the exam.

GATE EY Mock Test Link 2025

10 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: BM Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 BM exam, can go through the following direct link to appear for the exam.

GATE BM Mock Test Link 2025

10 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: XH Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 XH exam, can go through the following direct link to appear for the exam.

10 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: GE Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 GE exam, can go through the following direct link to appear for the exam.

GATE GE Mock Test Link 2025

09 45 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: EC Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 EC exam, can go through the following direct link to appear for the exam.

GATE EC Mock Test Link 2025

09 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Exam Starts

GATE 2025 February 1 shift 1 exam has started which will end at 12.30 PM. Till then the candidates are advised to stay connected with this live blog to get the latest updates about the unofficial answer key.

09 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: PI Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 PI exam, can go through the following direct link to appear for the exam.

GATE PI Mock Test Link 2025

09 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: ES Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 ES exam, can go through the following direct link to appear for the exam.

GATE ES Mock Test Link 2025

08 45 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: DA Mock Test Link

Candidates who will be appearing for the February 15 GATE 2025 DA exam, can go through the following direct link to appear for the exam.

GATE DA Mock Test Link 2025

08 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: AE Mock Test Link

Candidates who will be appearing for the February 2 GATE 2025 AE exam, can go through the following direct link to appear for the exam.

GATE AE Mock Test Link 2025

08 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: CY Mock Test Link

Candidates who will be appearing for the February 2 GATE 2025 CY exam, can go through the following direct link to appear for the exam.

GATE CY Mock Test Link 2025

08 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Check Day 2 Exam Schedule

Check out the shift-wise GATE 2025 February 2 exam schedule here in the given table:

07 45 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: When will shift 2 exam start?

GATE 2025 February 1 shift 2 exam will start at 2.30 PM and as per the schedule, CS2, MT, NM, IN and TF exam will be conducted.

07 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: EE Mock Test Link

Candidates who will be appearing for the February 2 GATE 2025 EE exam, can go through the following direct link to appear for the exam.

GATE EE Mock Test Link 2025

07 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: AR Mock Test Link

Candidates who will be appearing for the February 2 GATE 2025 AR exam, can go through the following direct link to appear for the exam.

GATE AR Mock Test Link 2025

07 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: PE Mock Test Link

Candidates who will be appearing for the February 2 GATE 2025 PE exam, can go through the following direct link to appear for the exam.

GATE PE Mock Test Link 2025

06 45 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: ME Mock Test Link

Candidates who will be appearing for the February 2 GATE 2025 ME exam, can go through the following direct link to appear for the exam.

GATE ME Mock Test Link 2025

06 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Facilities for Candidates with Scribe

• Candidates with a benchmark disability (not less than 40% disability) under the category of blindness, cerebral palsy, locomotor disability, are eligible to avail scribe
• Dyslexic candidates can also hire scribes. For the same, the dyslexic candidates should submit a proper dyslexic certificate issued by the competent authorities

06 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Important Instructions

• Candidates will be given login access at least 20 minutes before the starting of the exam. Candidates should utilize the time by reading all the questions and instructions then
• Candidates should not forget to carry all the required documents to the exam centre
• It is mandatory to reach to the exam centre by the reporting time
• Candidates should use the scribble pad for calculation and rough work. Once the exam will end, the candidates should return it to the invigilator

06 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Important Instructions that Candidates should not do

• Candidates should click on the “Save” button for submitting the responses. If the candidates proceed to the next question without clicking the “Save” option, then the responses will not be saved
• It will also be time consuming if they come back again to the previous questions to submit the response
• Candidates are not advised to mark the answers if they are not sure about it, otherwise the wrong answers will lead to deduct the marks
• If the candidates will find with any electronic device inside the GATE exam centre, then they will be debarred from the exam

05 30 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Items Not to Carry

Candidates do not carry the following objects to the GATE exam centre:

• Electronic gadgets such as Bluetooth devices, mobile phones
• Calculators
• Wrist watches
• Any kind of stationary objects, such as the log table, pencil etc. 

05 15 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Important Documents to Carry

Candidates should carry the following documents to the exam centre on GATE 2025 exam.

• GATE admit card 2025
• Photo ID card (Aadhar Card/ PAN Card/ Passport/ Voter ID card/ College ID or Employee ID)
• Passport sized photo
• Transparent water bottle
• Blue/ Black ball pen

05 00 AM IST - 01 Feb'25

GATE 2025 Unofficial Answer Key: Day 1 Exam

Today is GATE 2025 day 1 exam, which will be conducted in two shifts, Forenoon Session (9.30 AM to 12.30 PM) and afternoon session (2.30 PM to 5.30 PM).