List of top Physics Questions asked in CPET

The light emitted in the transition \(n = 3\) to \(n = 2\) in hydrogen is called \(H_\alpha\) light. The maximum work function a metal can have so that \(H_\alpha\) light can emit photoelectrons from it is:

If a laser beam has an intensity of \(2.5\times10^{14}\,\text{W/m}^{2}\), then the amplitude of the electric field and magnetic field in the beam is:

A transformer has 50 turns in the primary and 100 in the secondary. What will the voltage across the secondary be if the primary is connected to a 220 V DC supply?

The magnetic field at a point inside the 2.0 mH inductor coil becomes 0.80 of its maximum value in \(20\,\mu\text{s}\) when the inductor is joined to a battery. Then the resistance of the circuit is:

The wave function of a particle in a region classically forbidden region is __________.

The value of electric charge and strangeness of the d-quark is:

A long wire carries a current of 4.00 A. The energy stored in the magnetic field inside the volume of \(1\,\text{mm}^{3}\) at a distance of 10 cm from the wire is given by:

The probability current density (probability density current) in one dimension is given by:

Einstein's law and Debye's law of specific heat merge with Dulong-Petit's law at:

The average energy of Planck's oscillator is given by:

De-Broglie wavelength for thermal neutrons is:

The expectation value of \(p_x\) of the momentum of a particle trapped in a one-dimensional box is:

The quantum operator for energy is:

The two eigenvalues of the matrix \(\begin{pmatrix} 1 & 1 \\ 1 & 1 \end{pmatrix}\) are:

Using the vector atom model, the possible values of the magnitude of angular momentum of an electron in the \(f\) shell are:

An electron enters a uniform magnetic field of flux density \(1.2\ \text{Wb/m}^2\). The energy difference (in eV) between electrons having spins parallel and anti-parallel to the field is:
(Given: \(\mu_B = 9.3 \times 10^{-24}\ \text{J/T}\))

A meter stick is at an angle of \(45^\circ\) to the \(x\)-axis in its rest frame. The rod moves with a speed of \(\dfrac{c}{\sqrt{2}}\) along the \(+x\)-direction w.r.t. a frame \(S\). The length of the rod in \(S\) is:

The rank of the following matrix is:
\[\begin{pmatrix} 1 & 5 & 1 \\ 2 & 1 & 1 \\ 5 & 6 & 2 \end{pmatrix}\]

An AC generator with output voltage \(V\) and frequency \(f\) is connected to the plates of an air-filled parallel plate capacitor of plate area \(A\) and plate separation \(d\). The maximum value of the displacement current is:

A particle of mass \(m\) moves under a potential \(V(x)\). The Lagrangian of the system is given by \(L = \tfrac{1}{2}m\dot{x}^2 - V(x)\). According to Lagrange's equation of motion, which of the following is the correct equation of motion for the particle?

A coordinate \(q_i\) is called cyclic (or ignorable) if:

A cylinder of length \(L\) is made up of an inner core of steel of radius \(r\) and an outer sheath of copper of thickness \(r\). The resistivities of steel and copper are \(\rho_1\) and \(\rho_2\) respectively. The total resistance of the cylinder is:

Find \( \nabla\phi \) if \( \phi = \log r \), where \( r = |\vec{r}| \):

The Laplace transform of \( e^{-at} \) is:

Find the value of the integral
\[\int_{-1}^{1} x\,P_n(x)\,P_{n-1}(x)\,dx\]