List of top Physics Questions

In order to obtain time constant of $10\, s$ in an $R-C$ circuit containing a resistance of $10^3 \Omega$ , the capacity of the condenser should be
Two bodies are thrown up at angles of $40^{\circ}$ and $60^{\circ}$ respectively, with the horizontal. If both bodies attain same vertical height, then ratio of velocities with which these are thrown is
A flat mirror revolves at a constant angular velocity making $2\, rev\, s^{-1}.$ With what velocity will a light spot move along a spherical screen with a radius of $10\, m$, if the mirror is at a centre of curvature of the screen ?
The distance between the sun and the earth be $r$, then the angular momentum of the earth around the sun is proportional to
A $1\,m$ long steel wire of cross-sectional area $ 1\,mm^{2}$ is extended by $1\, mm$. If $ Y=2\times 10^{11}N/m^{2}$ , then the work done is :
In which of the following process, convection does not take place primarily?
A machine which is $75\%$ efficient, uses $12\, J$ of energy in lifting $1 \,kg$ mass through a certain distance. The mass is then allowed to fall through the same distance. The velocity at the end of its fall is
In an equilateral triangle $ABC$, $ F_{1},F_{2} $ and $ F_{3} $ are three forces acting along the sides $AB, BC$ and $AC$ as shown in the given figure. What should be the magnitude of $F_3$, so that the total torque about $ O $ is zero ?
The torque of force $\vec{ F }=(2 \hat{ i }-3 \hat{ j }+4 \hat{ k }) N$ acting at a point $\vec{ r }=(3 \hat{ i }+2 \hat{ j }+3 \hat{ k }) m$ about origin is
$300\, J$ of work is done in sliding a $2 \,kg$ block up an inclined plane of height $10 \,m$. The work done against friction is ( Take $g=10\, m / s ^{2}$ )
We wish to see inside an atom. Assuming the atom to have a diameter of $100 \,pm$, this means that one must be able to resolve a width of say $10\, pm$. If an electron microscope is used, the minimum electron energy required is about
Suppose refractive index $\mu$ is given as $\mu=A+\frac{B}{\lambda^{2}}$, where $A$ and $B$ are constants and $\lambda$ is wavelength then the dimensions of $B$ are same as that of
If a star can convert all the He nuclei completely into oxygen nuclei. The energy released per oxygen nuclei is : (Mass of the helium nucleus is 4.0026 amu and mass of oxygen nucleus is 15.9994 amu)
An infinitely long cylinder is kept parallel to an uniform magnetic field B directed along positive z-axis. The direction of induced current as seen from the 2-axis will be
In $ 1\,m $ long open pipe what is the harmonic of resonance obtained with a tuning fork of frequency $ 480\,Hz $ ?
A body of mass $ 4\,kg $ moving with velocity $ 12\,m/s $ collides with another body of mass $ 6 \,kg $ at rest. If two, bodies stick together after collision, then the loss of kinetic energy of system is
A particle moves in a circular path with decreasing speed. Choose the correct statement
Calorie is defined as the amount of heat required to raise temperature of 1 g of water by 1$^{\circ}$C and it is defined under which of the following conditions ?
Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field through both coils if the same current is flown :
The potential difference between points $A$ and $B$ is:
The dimensional formula for Youngs modulus is:
A police jeep is chasing with velocity of $45\, km/h$ a thief in another jeep moving with velocity $153\,km/h$. Police fires a bullet with muzzle velocity of $180\,m/s$ The velocity it will strike the car of the thief is:
A plane glass slab is kept over various colour letters, the letter which appears least raised is:
A sphere of diameter $0.2\,m$ and mass $2\, kg$ is rolling on an inclined plane with velocity $ \upsilon =0.5\, m/s$. The kinetic energy of the sphere is:
The radius of the convex surface of planoconvex lens is $20\,cm$ and the refractive index of the material of the lens is $1.5$. The focal length is: