List of top Questions asked in TS PGECET- 2026

A metal has one free electron per atom, density $\rho = 0.97 \text{ g/cm}^3$ and molar mass $M = 39 \text{ g/mol}$. Calculate the Fermi energy $E_F$ of the metal:}

A metal has free electron density $n = 8.5 \times 10^{28} \text{ m}^{-3}$ and relaxation time $\tau = 2.5 \times 10^{-14} \text{ s}$. Calculate its electrical conductivity ($\sigma$):}

The refractive index of a material is defined as:

Which of the following is not a mechanism of polymerization?

In a fiber-reinforced composite, the primary role of the matrix is to

The band gap of an intrinsic semiconductor increases with:

The point on the stress-strain curve beyond which the material will not return to its original shape when the load is removed is called the:

Free electron theory treats conduction of electrons in metals as:

Electrical conductivity in metals primarily depends on

During the recovery stage of annealing, which property changes the most significantly?

Which material typically exhibits a distinct upper and lower yield point in its stress-strain curve?

The area under the engineering stress-strain curve up to the point of fracture represents

Which mechanism involves the movement of atoms to form a mirror image of the crystal structure across a plane?

In which structure the Copper and Aluminum crystallize?

Grain refinement improves strength mainly by

Composites are designed primarily to

The active medium in a semiconductor laser is

Hot working differs from cold working because it

Quantum well lasers achieve lower threshold current because of

Proof stress is used when

Aluminum alloy stress–strain curve shows

The number of atoms per unit cell in FCC structure is

The number of crystal systems in three dimensions is

Cross-slip is possible only for

Dislocation climb occurs due to