List of top Questions asked in GATE ES

As per the United Nations agenda for sustainable development adopted in September 2015, the number of Sustainable Development Goals (SDGs) _____ are year to achieve them is and the proposed target year to achieve them is ______.

Which one of the following is NOT a greenhouse gas?

As per the United Nations Environmental Program (UNEP) guidelines 2004, the maximum size of microplastics is ________.

The costliest functional element in an urban centralized Municipal Solid Waste management infrastructure for a typical Indian Tier I city is ________.

The eigen values of the matrix \(\begin{bmatrix}4 & 3 \\3 & 4 \end{bmatrix} \) are

If X is a vector, and A and B are linear operators; then the correct mathematical relationship(s) is/are

In the context of fluid flow, which of the following statement(s) is/are correct?

In a rectangular open channel, the flow is critical, and the flow depth is 2 m. Select the correct statement(s)

With respect to particle settling in wastewater treatment systems; the correct statement(s) is/are

The equipment that can be used to control particulate air pollution in an industrial unit is/are

Which is/are the secondary air pollutant(s)?

As per the Hazardous Waste (Management and Handling) Rules, 2016, of India, which is/are the characteristic(s) that must be exhibited by a waste to be classified as a "characteristic" hazardous waste?

$f(x) = x^3 – 4.5x^2 - 12x$ has a local maximum at x = ___________(an integer value) in the range x = − 2 to + 2

Consider the equation - $\farc{dy}{dx}- x^2 + e^x = 0;$ with y =1 at x = 0.
The value of y at x = 1 is _________. (rounded off to 2 decimal places).
Take the value of e (base of natural logarithm) as 2.7.

A municipal solid waste digester generates 1000 kg of methane gas. The volume of the tank needed to store this gas at 30°C and 3 atmospheric pressure is ________ liters (an integer value).
Use R=0.082 L-atm/mole-K, Atomic weights of C=12, and H=1

A Class-A pan was setup adjacent to a lake for measuring evaporation losses in the lake. The depth of water in the pan at the beginning of a certain week was 250 mm. In that week, there was a rainfall event with 10 mm depth. Water depth in the pan at the end of the week was 240 mm. The pan coefficient is 0.8.
The estimated lake evaporation during the week was |_________mm (an integer value).

A population (with mean μ) follows normal distribution. Ten samples (N) are drawn at random with a mean value of "x" and standard deviation of "S". Following table provides the confidence limits, C(t) of the cumulative probability function for Student's t - distribution two-tailed test with degree of freedom, D.
Which one of the following expression is correct for testing the null hypothesis $H_o: μ = 0$ at 10% significance level?

D	C(t)
	0.9	0.95	0.975
9	1.38	1.83	2.26
10	1.37	1.81	2.23
11	1.36	1.80	2.20

Which one is the solution y(x) for the following ordinary differential equation and the specified boundary conditionmys?
\(\frac{d^2y}{dx^2} -3 \frac{dy}{dx}+2y = 2e ^{-x}; y(0) =2; (\frac{dy}{dx}_{x=0})=1\)

A saturated \(CaCO_3 \)stock solution is existing at 25°C. In one experiment (i) 25 g \(Na_2CO_3 \)is added to the stock solution. In another experiment (ii) 25 g \(Na_2SO_4\) is added to the stock solution. Select the correct statement from the following.

Consider second order kinetics ($r = −kC^2$) under steady state condition. The ratio of volume of a complete mixed reactor (CMR) to that of a plug flow reactor (PFR) to achieve 90% reduction in the concentration is _______ .
Inlet concentrations in both the reactors are same.

Consider two horizontal layers of an aquifer as shown in figure. Each layer is isotropic and homogeneous. Flow is parallel to the stratification. Thickness and horizontal hydraulic conductivity of layer-1 are $h_1$i and $K_1$, respectively. Thickness and horizontal hydraulic conductivity of layer-2 are $h_2$ and $K_2$, respectively, where $h_1$ is not equal to $h_2$. The equivalent horizontal conductivity $K_x$ for the aquifer system is given by _____

A gravity settling chamber of height ‘H' and length ‘L' is designed to control particulate air pollution. In the chamber, the horizontal velocity of air flow is $'V_h'$ and terminal settling velocity of the target particle is $'V_ť$. Which one of the following expressions is the correct concept used to calculate the minimum size of the target particle that will be removed with 100% efficiency?

Consider the function f(x) = ln(sin(x)). Expand f(x+h) using Taylor's series. In this context, the correct statement(s) is/are

Enzymes with the class of enzymes are listed in the table. Enzyme Class of Enzyme

Enzymes	class of enzymes
(a) Lactate dehydrogenase	(i) Isomerases
(b) Alanine racemase	(ii) Transferases
(c) Lipase	(iii) Oxidoreductases
(d) Hexokinase	(iv) Hydrolases

Select the correct match(es)

With reference to disinfection, which of the following statement(s) is/are CORRECT?