Browse and search thousands of solved questions for your preparation.
Free questions with full explanations — locked behind signup to protect quality.
A horizontal platform is rotating with uniform angular velocity around the vertical axis passing through its centre. At some instant of time a viscous fluid of mass $m$ is dropped at the centre and is allowed to spread out and finally fall. The angular velocity during this period:
The moment of inertia of a thin rod about an axis passing through its mid-point and perpendicular to the rod is $2400\text{ g cm}^2$. The length of the $400\text{ g}$ rod is nearly:
A black body is at a temperature of $5760\text{ K}$. The energy of radiation emitted by the body at a wavelength of $250\text{ nm}$ is $U_1$, at a wavelength of $500\text{ nm}$ is $U_2$ and that at $1000\text{ nm}$ is $U_3$. Given Wien's constant $b=2.88 \times 10^6\text{ nm K}$, which of the following is correct?
The net impedance of the circuit (as shown in the figure) will be:
An AC source is connected to the given circuit. The value of $\phi$ will be:
Three identical spherical shells, each of mass $m$ and radius $r$ are placed as shown in the figure. Consider an axis $XX'$, which is touching two shells and passing through the diameter of the third shell. The moment of inertia of the system consisting of these three spherical shells about the $XX'$ axis is:
The M.I. of a body about the given axis is $1.2 \text{ kg m}^2$. Initially, the body is at rest. In order to have a rotational kinetic energy of 1500 J, an angular acceleration of $25 \text{ rad/s}^2$ must be applied about that axis for a duration of:
In the given circuit, the reading of voltmeter V1 and V2 are 300 V each. The reading of the voltmeter V3 and ammeter A are respectively:
L, C and R represent the value of inductance, capacitance, and resistance, respectively. The factor which has the same dimensions as that of the inverse of the resonance frequency is:
A solid sphere is in rolling motion. In rolling motion, a body possesses translational kinetic energy ($K_t$) as well as rotational kinetic energy ($K_r$) simultaneously. The ratio $K_t : (K_t + K_r)$ for the sphere will be:
Consider a system of two particles having masses $m_1$ and $m_2$. If the particle of mass $m_1$ is pushed towards the centre of mass of particles through a distance $d$, by what distance would the particle of the mass $m_2$ move so as to keep the centre of mass of particles at the original position?
From a circular disc of radius $R$ and mass $9M$, a small disc of mass $M$ and radius $R/3$ is removed concentrically. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through its centre is:
A transformer is used to light a 100 W and 110 V lamp from a 220 V main. If the main current is 0.5 A, the efficiency of the transformer is approximately:
A disc of radius $2\text{ m}$ and mass $100\text{ kg}$ rolls on a horizontal floor. Its centre of mass has speed of $20\text{ cm/s}$. How much work is needed to stop it?
An object flying in the air with velocity $(20\hat{i} + 25\hat{j} - 12\hat{k})$ suddenly breaks into two pieces whose masses are in the ratio of $1:5$. The smaller mass flies off with a velocity $(100\hat{i} + 35\hat{j} + 8\hat{k})$. The velocity of the larger piece will be:
A solid sphere, disc, and solid cylinder all of the same mass and made up of the same material are allowed to roll down (from rest) on an inclined plane, then:
Let En = -(me^4)/(8ε_0^2 n^2 h^2) be the energy of the nth level of H-atom. If all the H-atoms are in the ground state and radiation of frequency (E2 - E1)/h falls on it, then: (a) it will not be absorbed at all. (b) some of the atoms will move to the first excited state. (c) all atoms will be excited to the n=2 state. (d) no atoms will make a transition to the n=3 state. Choose the correct option:
The energy of ground electronic state of hydrogen atom is -13.6 eV. The energy of the first excited state will be:
Which among the curves shown in the figure represents electrostatic field lines?
A transverse wave propagating along the $x$-axis is represented by: $y(x,t) = 8.0\sin(0.5\pi x - 4\pi t - \frac{\pi}{4})$, where $x$ is in meters and $t$ in seconds. The speed of the wave is: