List of top Physics Questions

A particle is released from a height $h$. At a certain height, its kinetic energy is two times its potential energy. Height and speed of the particle at that instant are
A flywheel rotates with a uniform angular acceleration. Its angular velocity increases from $20\pi \, { rad\, s^{-1}}$ to $40\pi \, { rad\, s^{-1}}$ in 10 seconds. How many rotations did it make in this period?
Which one of the following substances has the largest specific heat?
The wavefront of a distant source of unknown shape is approximately
The temperature of two bodies $A$ and $B$ are respectively, $727?C$ and $327?C$. The ratio $H_A : H_B$ of the rates of heat radiated by them is
A copper rod of length $l$ is rotated about the end perpendicular to the uniform magnetic field $B$ with constant angular velocity $\omega$. The induced e.m.f. between the two ends is
Let $v_{rms}, v_{mp}$ and $v_{avg}$ represent the root mean square, the most probable and the average velocities respectively, in case of a gaseous system in equilibrium at certain temperature. Then, $(v_{rms})^2 : (v_{mp})^2 : (v_{avg})^2$ is
A circular coil of radius $0.1\, m$ has $80$ turns of wire. If the magnetic field through the coil increases from $0\, to\, 2$ tesla in $0.4 \,s$ and the coil is connected to a $11 \,\Omega$ resistor, what is the current flow through the resistor during the 0.4 s?
Two identical circular coils $A$ and $B$ are kept on a horizontal tube side by side without touching each other. If the current in the coil $A$ increases with time, in response, the coil $B$
The width of the depletion region in a p-n junction diode is
A truck accelerates from speed $\upsilon \,to\, 2\upsilon$. Work done in during this is
A radioactive substance emits $100$ beta particles in the first $2$ seconds and $50$ beta particles in the next $2$ seconds. The mean life of the sample is
Radii of curvature of a converging lens are in the ratio $1 : 2$. Its focal length is $6 \,cm$ and refractive index is $1.5$. Then its radii of curvature are
A series combination of resistor $(R)$ and capacitor $(C)$ is connected to an $AC$ source of angular frequency $'\omega'$. Keeping the voltage same, if the frequency is changed to $\frac{\omega}{3}$ , the current becomes half of the original current. Then the ratio of the capacitive reactance and resistance at the former frequency is
The wavelength $\lambda_e$ of an electron and $\lambda_P$ of a photon of same energy E are related by:
When a proton is released from rest in a room, it starts with an initial acceleration $a_0$ towards west. When it is projected towards north with a speed $v_0$ it moves with an initial acceleration $3a_0$ towards west. The electric and magnetic fields in the room are:
Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1m, 2m, 4m, 8m, ...., respectively, from the origin. The resulting gravitational potential due to this system at the origin will be
An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass $1\, kg$ moves with a speed of $12 \, ms^{-1}$ and the second part of mass $2 \,kg$ moves with $8 \, ms^{-1}$ speed. If the third part files off with $4 \, ms^{-1}$ speed, then its mass is :
The heart is pumping blood at x kg per unit time, with a constant velocity v. The force required is
The transverse displacement of a string fixed at both ends is given by $y=0.6 \sin \left(\frac{2 \pi x}{3}\right) \cos (120 \pi t)$ where $x$ and $y$ are in metres and $t$ is in seconds. The length of the string is $1.5\, m$ and its mass is $3.0 \times 10^{-2} kg$. The tension in the string is equal to
A man of mass \(100 \,kg\). is standing on a platform of mass \(200 \,kg\). Which is kept on a smooth ice surface. If the man starts moving on the platform with a speed \(30 \,m/sec\) relative to the platform then calculate with what velocity relative to the ice the platform will recoil?
The motion of a particle along a straight line is described by equation $ x = 8 + 12t - t^3 $ where $x$ is in metre and $t$ in second. The retardation of the particle when its velocity becomes zero is
The instantaneous values of alternating current and voltages in a circuit are given as $i=\frac{1}{\sqrt2}\sin(100\pi t)$ ampere $e=\frac{1}{\sqrt2}\sin(100\pi t+\frac{\pi}{3})$ Volt . The average power in watts consumed in the circuit is
Two sources of sound placed close to each other, are emitting progressive waves given by $y _{1}=4 \sin 600\, \pi t$ and $y _{2}=5 \sin 608\, \pi t :$ An observer located near these two sources of sound will hear
This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements. It is not possible to make a sphere of capacity $1$ farad using a conducting material. It is possible for earth as its radius is $6.4 \times 10^6\,m$.