List of top Physics Questions

A disc of moment of inertia 4 kg \( \text{m}^2 \) revolving with 16 rad/s is placed on another disc of moment of inertia 8 kg \( \text{m}^2 \) revolving with 4 rad/s. The angular frequency of the composite disc is
An electric current \( I \) enters and leaves a uniform circular wire of radius \( r \) through diametrically opposite points. A charged particle \( q \) moves along the axis of the circular wire and passes through its center with speed \( v \). The magnetic force on the particle when it passes through the center has a magnitude
A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5 A, then the average force on each electron in the coil due to the magnetic field is
A cell of emf 2V is connected with a load of resistance 1.5Ω. The power delivered by the cell to the load is maximum, then power transferred to the load is
The resultant of two forces acting at an angle of \( 120^\circ \) is \( 10 \, \text{kg-W} \) and is perpendicular to one of the forces. That force is
Two guns P and Q can fire bullets at speeds 2 km/s and 4 km/s, respectively. From a point on a horizontal ground, they are fired in all possible directions. The ratio of maximum or areas covered by the bullets fired by the two guns, on the ground is
The AC voltage across a resistance can be measured using a
A sample of hydrogen atom in its ground state is radiated with photons of $10.2$ eV energies. The radiation from the sample is absorbed by excited ionized He+. Then which of the following statement(s) is/are true?
Two wires $A$ and $B$ of the same length are made of the same material. The Load ($F$) vs. elongation ($x$) graph for these two wires is shown in the figure. Then which of the following statement(s) is/are true?
Two wires A and B of the same length are made of same material Load
A hemisphere of radius $R$ is placed in a uniform electric field $E$ so that its axis is parallel to the field. Which of the following statement(s) is/are true?
hemisphere of radius R is placed in a uniform electric field
A particle is moving in the $x$-$y$ plane according to $r = b \cos \omega t \hat{i} + b \sin \omega t \hat{j}$. Where $\omega$ is constant. Which of the following statement(s) is/are true?
As shown in the figure, a rectangular loop of length $a$ and width $b$ and made of a conducting material of uniform cross-section is kept in a horizontal plane where a uniform magnetic field of intensity $B$ is acting vertically downward. The resistance per unit length of the loop is $\lambda \, \Omega / m$. If the loop is pulled with uniform velocity $v$ in a horizontal direction, which of the following statement(s) is/are true?
rectangular loop of length 'a' and width 'b' and made of a conducting material of uniform cross-section
One mole of an ideal monatomic gas expands along the polytrope $P V^3 = \text{constant}$ from $V_1$ to $V_2$ at a constant pressure $P_1$. The temperature during the process is such that molar specific heat $C_v = \frac{3R}{2}$. The total heat absorbed during the process can be expressed as
The kinetic energy ($E_k$) of a particle moving along the X-axis varies with its position ($X$) as shown in the figure. The force acting on the particle at $X = 10$ m is
particle moving along the X-axis varies with its position
Three concentric metallic shells $A$, $B$, and $C$ of radii $a$, $b$, and $c$ have surface charge densities $+\sigma$, $-\sigma$, and $\sigma+$ respectively. The potential of shell $B$ is
Three concentric metallic shells
A horizontal semi-circular wire of radius $r$ is connected to a battery through two similar springs $X$ and $Y$ to an electric cell, which sends current $I$ through it. A vertically downward uniform magnetic field $B$ is applied on the wire, as shown in the figure. What is the force acting on each spring?
A horizontal semi-circular wire of radius
A golf ball of mass $50$ gm placed on a tee is struck by a golf club. The speed of the ball as it leaves the tee is $100$ m/s, and the time of contact on the ball is $0.02$ s. If the force decreases to zero linearly with time, then the force at the beginning of the contact is
Find the equivalent capacitance between $A$ and $B$ of the following arrangement:
equivalent capacitance
A particle is moving in an elliptical orbit as shown in the figure. If $p$, $L$, and $r$ denote the linear momentum, angular momentum, and position vector of the particle (from focus $O$) respectively at a point $A$, then the direction of $\alpha = p \times L$ is along
particle is moving in an elliptical orbit
The Entropy ($S$) of a black hole can be written as $S = \beta k_B A$, where $k_B$ is the Boltzmann constant and $A$ is the area of the black hole. Then $\beta$ has dimension of
If the kinetic energies of an electron, an alpha particle, and a proton having the same de-Broglie wavelength are $\varepsilon_1, \varepsilon_2, \varepsilon_3$ respectively, then
Suppose in a hypothetical world the angular momentum is quantized to be even integral multiples of $\frac{h}{2}$. The largest possible wavelength emitted by hydrogen atoms in the visible range in a world according to Bohr's model will be (consider $h_e = 1224$ MeV-fm)
In a Young's double slit experiment, the intensity of light at a point on the screen where the path difference between the interfering waves is $\lambda$ (where $\lambda$ is the wavelength of light used) is $1$. The intensity at a point where the path difference is $\frac{\lambda}{4}$ will be (assume two waves have the same amplitude)
Given: The percentage error in the measurements of A, B, C, and D are respectively 4%, 2%, 3%, and 1%. The relative error in $Z = \frac{A^4 B^{1/3}}{C D^{3/2}}$ is
A Zener diode having a breakdown voltage $V_z = 6$ V is used in a voltage regulator circuit as shown in the figure. The minimum current required to pass through the Zener to act as a voltage regulator is $10$ mA and the maximum allowed current through the Zener is $40$ mA. The maximum value of $R_\delta$ for Zener to act as a voltage regulator is
A Zener diode having a breakdown voltage