List of top Physics Questions

A body is thrown vertically up with certain initial velocity. The potential and kinetic energies of the body are equal at a point P in its path. If the same body is thrown with double the velocity upwards, the ratio of potential and kinetic energies of the body when it crosses the same point, is
A table tennis ball which has been covered with a conducting paint is suspended by a silk thread so that it hangs between two metal plates. One plate is earthed. When the other plate is connected to a high voltage generator, the ball
Millikan's oil-drop experiment established that
The ground state energy of hydrogen atom is -13.6 eV. When its electron is in the first excited state, its excitation energy is
Two nuclei have their mass numbers in the ratio of $ 1:3 $ . The ratio of their nuclear densities would be
The radius of curvature of the convex face of a planoconvex lens is $ 15 \,cm $ and the refractive index of the material is $ 1.4 $ . Then the power of the lens in dioptre is
The ratio of the nuclear radii of elements with mass numbers $216$ and $125$ is
The moment of inertia of a thin circular disc about an axis passing through its center and perpendicular to its plane is $1$. Then, the moment of inertia of the disc about an axis parallel to its diameter and touching the edge of the rim is
The coefficient of thermal conductivity of copper is $9$ times that of steel. In the composite cylindrical bar shown in the figure, what will be the temperature at the junction of copper and steel ?
A fish in water (refractive index $n$) looks at a bird vertically above in the air. If $y$ is the height of the bird and $x$ is the depth of the fish from the surface, then the distance of the bird as estimated by the fish is
A body is projected vertically upwards. The times corresponding to height $h$ while ascending and while descending are $t_1$ and $t_2$ respectively. Then the velocity of projection is ($g$ is acceleration due to gravity).
A bullet emerge from a barrel of length $1.2\, m$ with a speed of $640\, ms ^{-1}$. Assuming constant acceleration, the approximate time that it spends in the barrel after the gun is fired is
When sound is produced in an aeroplane moving with a velocity of $200 \,m/s$ horizontal its echo is heard after $ 10\sqrt{5}\,s. $ If velocity of sound in air is the elevation of aircraft is
A battery of e. m. f. $E$ and internal resistance $r$ is connected to an external resistance $R$ the condition for maximum power transfer is
The electric potential inside a conducting sphere
If $ g $ is the acceleration due to gravity on earth?s surface, the gain of the potential energy of an object of mass $ m $ raised from the surface of the earth to a height equal to the radius $ R $ of the earth is
A hollow sphere is filled with water through the small hole in it. It is then hung by a long thread and made to oscillate. As the water slowly flow out of the hole at the bottom, the period of oscillation will
The graph between the time period and the length of a simple pendulum is
Which of the following while in motion cannot be deflected by magnetic field ?
The charge carriers in a $ p $ -type semiconductor are
The charge carriers in a p-type semiconductor are
The binary number $10111$ is equivalent to the decimal number
The speed of sound in hydrogen at NTP is $1270 \,ms$ Then, the speed in a mixture of hydrogen and oxygen in the ratio $4 : 1$ by volume will be
A body of mass 10 kg initially at rest acquires velocity $10 ms^{-1}$. What is the work done
A block (5) is attached to two unstretched springs $ S_1 \, \, and \, \, S_2 $ with spring constants k and 4k, respectively. The other ends are attached to two supports $ M_1 $ and $ M_2 $ not attached to the walls. The springs and supports have negligible mass. There is no friction anywhere. The block B is displaced towards wall 1 by a small distance x and released. The block returns and moves a maximum distance y towards wall 2. Displacements x and y are measured with respect to the equilibrium position of the block B. The ratio $\frac{y}{x}$ is