List of top Physics Questions

A bullet of mass $m$ moving with velocity $v$ strikes a suspended wooden block of mass $M$. If the block rises to a $S$ height the initial velocity of the block will be

A body falls freely from the top of a tower. It covers $36\%$ of the total height in the last second before striking the ground level. The height of the tower is

The fundamental frequency of a closed pipe is $220 \,Hz$. If $\frac{1}{4}$ of the pipe is filled with water, the frequency of the first overtone of the pipe now is

A winding wire which is used to frame a solenoid can bear a maximum $10\, A$ current. If length of solenoid is $80\, cm$ and its cross-sectional radius is $3\, cm$ then required length of winding wire is $(B=0.2\, T)$

A battery is connected to a uniform resistance wire $AB$ and $B$ is earthed. Which one of the graphs below shows how the current density $J $ varies along $AB$?

An inductor $ L,\,\,a $ capacitor of $ 20\mu F $ and a resistor of $ 10\Omega $ are connected in series with an $AC$ source of frequency $ 50\,Hz $ . If the current is in phase with the voltage, then the inductance of the inductor is

A rifle shoots a bullet with a muzzle velocity of $ 500\,m{{s}^{-1}} $ at a small target $ 50\,m $ away. To hit the target the rifle must be aimed (take$ g=10\,m{{s}^{-2}}) $

In an $ AC $ circuit the potential difference V and current i are given respectively by $ V=100\sin (100t) $volt and $ i=100\sin \left( 100t+\frac{\pi }{3} \right)mA $ The power dissipated in the circuit will be

A particle is moving with velocity $\vec{v} = k\left(y\hat{i} + x\hat{j}\right),$ where $k$ is a constant. The general equation for its path is

A block of mass $10\, kg$ is moving in $x$-direction with a constant speed of $10\, m / s$. It is subjected to a retarding force $F=-0.1 \times J / m$ during its travel from $x=20\, m$ to $x=30\, m$. Its final kinetic energy will be :

A $12\, HP$ motor has to be operated $8\, h /$ day. How much will it cost at the rate of $50$ paise/kWh in 10 days?

When an ideal monoatomic gas is heated at consant pressure, fraction of heat energy supplied which increases the internal energy of gas, is

A body of mass $m$ rises to a height $h=\frac{R}{5}$ from the earth's surface where $R$ is earth's radius. If $g$ is acceleration due to gravity at the earth's surface, the increase in potential energy will be

The ratio of the dimensions of Plancks constant and that of the moment of inertia is the dimensions of

Application of a forward bias to a $p-n$ junction

A network of four capacitors of capacities equal to $C_{1}=C, C_{2}=2 C, C_{3}=3 C$ and $C_{4}=4 C$ are connected to a battery as shown in the figure.

The ratio of the charges on $C_{2}$ and $C_{4}$ is

The work functions for metals $A, B$ and $C$ are respectively $1.92\, eV,\, 2.0\, eV$ and $5\, eV$. According to Einstein's equation, the metal(s) which will emit photoelectrons for a radiation of wavelength $4100\,?$ is/are

A force $F$ is applied on the wire of radius $r$ and length $L$ and change in the length of wire is $l$. If the same force $F$ is applied on the wire of the same material and radius $2\, r$ and length $2\, L$, then the change in length of the other wire is

A $1\, kg$ stone at the end of $1\, m$ long string is whirled in a vertical circle at constant speed of $4\, m / s$. The tension in the string is $6\, N$, when the stone at $\left(g=10\, m / s ^{2}\right)$

The core of any transformer is laminated so as to

A nucleus of mass $M + \Delta m$ is at rest and decays into two daughter nuclei of equal mass $\frac{M}{2}$ each. Speed of light is c The binding energy per nucleon for the parent nucleus is $E_1$ and that for the daughter nuclei is $E_2$. Then

Light rays from a luminous (bright point) object in a denser medium of refractive index n at a depth h, outline a circle of radius equal to the depth, at the interface. The refractive index of denser medium is

Decrease in wavelength as a result of scattering is observed in

In Young's double slit experiment, intensities at a bright fringe is $I$. When one of the slits is dosed, intensity at the same position is