List of practice 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 basic principle of Cottnell's precipitator is
Among the following, which is least acidic ?
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 ratio of the nuclear radii of elements with mass numbers $216$ and $125$ is
Of all the environmental factors which is the most influential in determining the rate of transpiration ?
Whether a child died after normal birth or before birth can be confirmed by measuring
Intercalary meristem is a derivative of
Plants like Aegle mormelos, Ocimum sanctum and Ficus religiosa are a group of plants designated as
A ligand can also be regarded as
The IUPAC name for tertiary butyl iodide is
The overlapping of orbitals in benzene is of the type
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 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
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 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
Sodium nitrate on reduction with $Zn$ in presence of $NaOH$ solution produces $NH_3$ Mass of sodium nitrate absorbing $1$ mole of electron will be
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
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
The electric potential inside a conducting sphere