List of top Physics Questions

In a ferromagnetic material, below the curie temperature, a domain is defined as:
If e is the electronic charge, c is the speed of light in free space and h is Planck's constant, the quantity $\frac{1}{4\pi\epsilon_0}\frac{e^2}{hc}$ has dimensions of:
A stone is dropped from the top of a building. When it crosses a point 5 m below the top, another stone starts to fall from a point 25 m below the top. Both stones reach the bottom simultaneously. The height of the building is:
The diameter of a spherical bob is measured using a vernier callipers. 9 divisions of the main scale, in the vernier callipers, are equal to 10 divisions of vernier scale. One main scale division is 1 mm. The main scale reading is 10 mm and \(8^{th}\) division of vernier scale was found to coincide exactly with one of the main scale division. If the given vernier callipers has positive zero error of 0.04 cm, then the radius of the bob is ________ \(\times 10^{-2}\) cm.
A bandwidth of 6 MHz is available for A.M. transmission. If the maximum audio signal frequency used for modulating the carrier wave is not to exceed 6 kHz. The number of stations that can be broadcasted within this band simultaneously without interfering with each other will be ________.
A particle is moving with constant acceleration 'a'. Following graph shows \(v^2\) versus x (displacement) plot. The acceleration of the particle is ________ m/s\(^2\).
\begin{center} \includegraphics[width=0.35\textwidth]{graph_v2_x} \end{center}
A long solenoid with 1000 turns/m has a core material with relative permeability 500 and volume \(10^3\) cm\(^3\). If the core material is replaced by another material having relative permeability of 750 with same volume maintaining same current of 0.75 A in the solenoid, the fractional change in the magnetic moment of the core would be approximately \(\left( \frac{x}{499} \right)\). Find the value of x.
A resistor dissipates 192 J of energy in 1 s when a current of 4 A is passed through it. Now, when the current is doubled, the amount of thermal energy dissipated in 5 s is _________ J.
In a Young's double slit experiment, the slits are separated by 0.3 mm and the screen is 1.5 m away from the plane of slits. Distance between fourth bright fringes on both sides of central bright fringe is 2.4 cm. The frequency of light used is ________ \(\times 10^{14}\) Hz.
Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of the uncertainty in determining the position of an electron to that of a proton is proportional to :
Statement I : To get a steady dc output from the pulsating voltage received from a full wave rectifier we can connect a capacitor across the output parallel to the load \(R_L\).
Statement II : To get a steady dc output from the pulsating voltage received from a full wave rectifier we can connect an inductor in series with \(R_L\).
In the light of the above statements, choose the most appropriate answer from the options given below :
Choose the incorrect statement :
(a) The electric lines of force entering into a Gaussian surface provide negative flux.
(b) A charge 'q' is placed at the centre of a cube. The flux through all the faces will be the same.
(c) In a uniform electric field net flux through a closed Gaussian surface containing no net charge, is zero.
(d) When electric field is parallel to a Gaussian surface, it provides a finite non-zero flux.
Choose the most appropriate answer from the options given below :
A parallel plate capacitor of capacitance 200 \(\mu F\) is connected to a battery of 200 V. A dielectric slab of dielectric constant 2 is now inserted into the space between plates of capacitor while the battery remains connected. The change in the electrostatic energy in the capacitor will be ________ J.
Cross-section view of a prism is the equilateral triangle ABC shown in the figure. The minimum deviation is observed using this prism when the angle of incidence is equal to the prism angle. The time taken by light to travel from P (midpoint of BC) to A is ________ $\times 10^{-10}$ s. (Given, speed of light in vacuum $= 3 \times 10^8$ m/s and $\cos 30^\circ = \frac{\sqrt{3}}{2}$)
\begin{center} \includegraphics[width=0.3\textwidth]{prism_diagram} \end{center}
A sample of gas with $\gamma = 1.5$ is taken through an adiabatic process in which the volume is compressed from 1200 $cm^3$ to 300 $cm^3$. If the initial pressure is 200 kPa. The absolute value of the workdone by the gas in the process = ________ J.
A current of 1.5 A is flowing through a triangle, of side 9 cm each. The magnetic field at the centroid of the triangle is : (Assume that the current is flowing in the clockwise direction.)
If \(V_A\) and \(V_B\) are the input voltages (either 5 V or 0 V) and \(V_o\) is the output voltage then the two gates represented in the following circuits (A) and (B) are :
\begin{center} \includegraphics[width=0.5\textwidth]{logic_gates} \end{center}
The magnetic field vector of an electromagnetic wave is given by \( \vec{B} = B_0 \frac{\hat{i} + \hat{j}}{\sqrt{2}} \cos(kz - \omega t) \); where \(\hat{i}, \hat{j}\) represents unit vector along x and y-axis respectively. At \(t = 0\) s, two electric charges \(q_1\) of \(4\pi\) coulomb and \(q_2\) of \(2\pi\) coulomb located at \((0, 0, \frac{\pi}{k})\) and \((0, 0, \frac{3\pi}{k})\), respectively, have the same velocity of \(0.5\,c\,\hat{i}\), (where c is the velocity of light). The ratio of the force acting on charge \(q_1\) to \(q_2\) is :
For a body executing S.H.M. :
(a) Potential energy is always equal to its K.E.
(b) Average potential and kinetic energy over any given time interval are always equal.
(c) Sum of the kinetic and potential energy at any point of time is constant.
(d) Average K.E. in one time period is equal to average potential energy in one time period.
Choose the most appropriate option from the options given below :
A system consists of two identical spheres each of mass 1.5 kg and radius 50 cm at the ends of a light rod. The distance between the centres of the two spheres is 5 m. What will be the moment of inertia of the system about an axis perpendicular to the rod passing through its midpoint ?
Four identical hollow cylindrical columns of mild steel support a big structure of mass $50 \times 10^3\,\text{kg}$. The inner and outer radii of each column are 50 cm and 100 cm respectively. Assuming uniform local load distribution, calculate the compression strain of each column. [use $Y = 2.0 \times 10^{11}\,\text{Pa}$, $g = 9.8\,\text{m/s}^2$]
If \(R_E\) be the radius of Earth, then the ratio between the acceleration due to gravity at a depth 'r' below and a height 'r' above the earth surface is : (Given : \(r<R_E\))
A bob of mass 'm' suspended by a thread of length $l$ undergoes simple harmonic oscillations with time period T. If the bob is immersed in a liquid that has density $\frac{1}{4}$ times that of the bob and the length of the thread is increased by $1/3^{rd}$ of the original length, then the time period of the simple harmonic oscillations will be :
A block moving horizontally on a smooth surface with a speed of 40 m/s splits into two parts with masses in the ratio of \(1 : 2\). If the smaller part moves at 60 m/s in the same direction, then the fractional change in kinetic energy is :
A mixture of hydrogen and oxygen has volume 500 \(cm^3\), temperature 300 K, pressure 400 kPa and mass 0.76 g. The ratio of masses of oxygen to hydrogen will be :