List of top Questions asked in AP PGECET- 2026

The unit step response of a first-order system reaches 63.2% of its final value at time:

Dead time (transport delay) in a process control system causes:

The frequency at which maximum AR occurred is called

Which of the following is most suitable to measure a temperature of \(2500^\circ\text{C}\)?

A typical example of a physical system with under-damped characteristics is a ______

Consider the following equation \(2s^4 + s^3 + 3s^2 + 5s + 10 = 0\); How many roots does this equation have in the right half of s-plane?

The second order system with the transfer function \(1/(s^2 + 2s + 1)\) is a

Which of the following is an example for an unbounded input?

During Joule-Thomson expansion of gases _____

Non-isothermal plug flow reactor design requires solving simultaneously:

At a given temperature K$_1$, K$_2$ and K$_3$ are the equilibrium constants for the following reactions 1, 2 and 3 respectively:
CH$_4$(g) + H$_2$O(g) = CO(g) + 3H$_2$(g) ___(1)
CO(g) + H$_2$O(g) = CO$_2$(g) + H$_2$(g) ___(2)
CH$_4$(g) + 2H$_2$O(g) = CO$_2$(g) + 4H$_2$(g) ___(3)
Then the K$_1$, K$_2$ and K$_3$ are related as

In a non-ideal reactor modeled by the dispersion model, Peclet number represents:

For series reactions A $\to$ B $\to$ C, maximum concentration of intermediate B in a PFR occurs when:

Choose the option that correctly matches in Group 1 with those in Group 2
Group 1: (P) coking, (Q) poisoning, (R) sintering
Group 2: (I) prolonged exposure of catalyst to high temperature, (II) deposition of carbonaceous material on catalyst surface, (III) irreversible chemisorption of molecules on active sites of catalyst

At high Thiele modulus ($\phi \gg 1$), the effectiveness factor ($\eta$) approaches:

A first-order liquid-phase reaction (k = 0.1 min$^{-1}$) is carried out in a CSTR at 80% conversion. The space time required is:

The conversion for a first-order reaction in a PFR compared to CSTR (same volume) is:

Residence time distribution (RTD) function E(t) satisfies:

The dispersion number for plug flow must be ______

There is strong pore resistance, when the Thiele Modulus is ______

The dimensions of the rate constant for reaction 2A $\to$ B are litre/ (mol.min), the order of the reaction is ______

For the constant-density systems, the performance equations are identical for______

For the isothermal gas-phase reaction A $\to$ 3B, the fractional change in volume of the system between no conversion and complete conversion is ______

The term knuckle radius, is associated with ______

In an absorption column, the gas enters at y$_1$ = 0.10 and exits at y$_2$ = 0.01. The solvent enters pure (x$_2$ = 0). Using a liquid-gas ratio (L/G) of 2, the exit liquid mole fraction x$_1$ is: