List of top Physics Questions on Physics

A parallel plate capacitor having plate area of 50 cm$^2$ and separation of 0.1 mm is completely filled with a dielectric (dielectric constant $ K = 10 $). The capacitor is connected to a 10 kΩ resistance and an alternating voltage $ v = 10 \sin(100\pi t) $, as shown in the figure. The switch $ S $ is initially open and then closed at $ t = 0 $. The ratio of the displacement current in the capacitor, to the current in the resistance, at time $ t = \frac{2}{\pi} $ seconds is .......... (Round off to three decimal places).

An RC circuit is connected to two dc power supplies, as shown in the figure. With switch $ S $ open, the capacitor is fully charged. $ S $ is then closed at time $ t = 0 $. The voltage across the capacitor at $ t = 2.4 \, \text{ms} $ is ................ V (Round off to one decimal place).

A time independent conservative force $ \vec{F} $ has the form, $ \vec{F} = 3y\hat{i} + f(x, y)\hat{j} $. Its magnitude at $ x = y = 0 $ is 8. The allowed form(s) of $ f(x, y) $ is (are):

Four charges are placed very close to each other, as shown. The separation between the two charges on the y-axis is $ a $. The separation between the two charges on the x-axis is also $ a $. The leading order (non-vanishing) form of the electrostatic potential, at point $ P $, at a distance $ r $ from the origin ($ r \gg a $), is:

For the given circuit, the output $ Y $ is:

Let $(x, y)$ denote the coordinates in a rectangular Cartesian coordinate system $ C $. Let $(x', y')$ denote the coordinates in another coordinate system $ C' $ defined by
\[ x' = 2x + 3y, \quad y' = -3x + 4y \] The area element in $ C' $ is:

For the Boolean expression $ Y = A B C + A' B C + A B' C + A' B' C $, the number of combinations for which the output $ Y = 1 $ is .............. .

Twenty non-interacting spin $ \frac{1}{2} $ particles are trapped in a three-dimensional simple harmonic oscillator potential of frequency $ \omega $. The ground state energy of the system, in units of $ \hbar \omega $, is ......... .

Consider the following differential equation that describes the oscillations of a physical system:
\[ \alpha \frac{d^2y}{dt^2} + \beta \frac{dy}{dt} + \gamma y = 0 \] If $ \alpha $ and $ \beta $ are held fixed, and $ \gamma $ is increased, then:

The rms velocity of molecules of oxygen gas is given by $ v = \sqrt{\frac{3kT}{m}} $ at some temperature $ T $. The molecules of another gas have the same rms velocity at temperature $ T' = \frac{T}{16} $. The second gas is:

At $ t = 0 $, $ N_0 $ number of radioactive nuclei $ A $ start decaying into $ B $ with a decay constant $ \lambda_a $. The daughter nuclei $ B $ decay into nuclei $ C $ with a decay constant $ \lambda_b $. Then, the number of nuclei $ B $ at small time $ t $ (to the leading order) is:

Arrange the following telescopes, where $ D $ is the telescope diameter and $ \lambda $ is the wavelength, in order of decreasing resolving power:
I. $ D = 100\,\text{m}, \lambda = 21\,\text{cm} $
II. $ D = 2\,\text{m}, \lambda = 500\,\text{nm} $
III. $ D = 1\,\text{m}, \lambda = 100\,\text{nm} $
IV. $ D = 2\,\text{m}, \lambda = 10\,\text{mm} $

An object of density $ \rho $ is floating in a liquid with 75% of its volume submerged. The density of the liquid is:

One point charge (q) each, is placed along a line at 3 different points $x = 0$, $x = 2 \, \text{nm}$ and $x = 6 \, \text{nm}$. The force between two charges separated by 2 nm is 2 piconewton (pN). The magnitude of force (in pN) on the charge in the middle due to the other two charges is ..............

Consider two bodies with equal masses of $ 10^{12} $ kg each and R distance apart. Let G be the gravitational constant and $ V_0 $ be a constant with dimensions of energy. Which of the following represent(s) gravitational potential energy (V) between the bodies, such that Newton's law of gravitation is valid?

At a given time $ t $, velocity $ v(t) $ and acceleration $ a(t) $ of a particle undergoing simple harmonic motion are given by
\[ v(t) = -100 \sin \left( 20 t + \frac{\pi}{3} \right), \] \[ a(t) = -2000 \cos \left( 20 t + \frac{\pi}{3} \right). \] Assuming all quantities are in SI units, the amplitude of the oscillation is ............

Consider two particles, each of mass 20 g; the first particle is moving with a speed of 10 m/s along a one-dimensional track in the positive x-direction and collides with the second particle at rest. Assuming that the collision is elastic, the speed (in m/s) of the first particle after the collision is ...............

Consider a spherical particle of mass $ m $ and radius $ r $ moving in a medium. Its velocity at any time is given by $ v = v_0 \exp\left( -\frac{6 \pi X r t}{m} \right) $, where $ v_0 $ is the initial velocity of the particle. The dimensions of $ X $ are

The Zener current $ I_Z $ for the given circuit is .............. mA.

The flux of the function $ \mathbf{F} = (y^2) \hat{x} + (3xy - z^2) \hat{y} + (4yz) \hat{z} $ passing through the surface ABCD along $ \hat{n} $ is ............

During the charging of a capacitor C in a series RC circuit, the typical variations in the magnitude of the charge $q(t)$ deposited on one of the capacitor plates, and the current $i(t)$ in the circuit, respectively are best represented by

In the given phase diagram for a pure substance, regions I, II, III, IV, respectively represent

The output of the following logic circuit can be simplified to \[ \text{(Logic circuit diagram provided)} \]

A classical particle has total energy $ E $. The plot of potential energy $ U(r) $ as a function of distance $ r $ from the centre of force located at $ r = 0 $ is shown in the figure. Which of the regions are forbidden for the particle?

The decimal equivalent of the binary number 110.101 is ................