List of top Physics Questions

The centre of mass of a non uniform rod of length L whose mass per unit length $\lambda=\frac{Kx^2}{L},$ Where k is a constant and x is the distance from one end is :

The cause of the fractional atomic weight of elements is

The capacitors of capacitance $4\,\mu F$ and $6\,\mu F$ are connected in series. A potential difference of $500\, volt$ is applied to the outer plates of capacitor system. Then the charge on each capacitor is equal to

The capacity of a storage cell is expressed in :

The capacitance of a parallel plate capacitor is $5\,\mu F$. When a glass slab is placed between the plates of the capacitor, its potential difference reduces to $1/8$ of the original value. The thickness of the slab is equal to the separation between the plates. The value of the dielectric constant of glass is

The capacitance of a conductor in vacuum is $10\,F$. If it is put in a medium of relative permittivity $5$, the capacitance will be :

The breakdown in a reverse biased $p-n$ junction diode is more likely to occur due to

The breaking force for a wire of diameter D of a material is F. The breaking force for a wire of the same material of radius D is

The branch of optics dealing with the formation of images using the concept of straight line propagation of light is called:

The blades of a windmill sweep out a circle of area $A$. If the wind flows at a velocity $v$ perpendicular to the circle, then the mass of the air of density $\rho$ passing through it in time $t$ is

The average self-induced emf in a 25mH solenoid when the current in it falls from 0.2 A to 0 A in 0.01 second, is

The average depth of Indian ocean is about $3000\, m$. The fractional compression, $\frac{\Delta V}{V}$ of water at the bottom of the ocean is (Given : Bulk modulus of the water $= 2.2 ? 10^9 \,N \,m^{-2}$ and $g = 10 \,m\, s^{-2}$)

The area under acceleration-time graph represents the

The area of cross-section of a wire of length 1.1 m is 1 $mm^2$. It is leaded with 1 kg of Young's modulus of copper is $1.1\times10^i Nm^\circ$ , then the increase in length will be $(ifg = 10{ms^-2})$

The angular dispersion will be maximum in the following pairs of colours is

The angle of minimum deviation of a prism depend upon:

The angle of dip at a place on the earth's surface gives

The amplitude of a damped oscillator becomes one half after $t$ second. If the amplitude becomes $(1/n)$ after $3 \,t$ second, then $n$ is equal to

The adjacent graph shows the extension $(\Delta l)$ of a wire of length 1 m suspended from the top of a roof at one end with a load W connected to the other end. If the cross-sectional area of the wire is $10^{-6} m^2 , $ calculate the Young's modulus of the material of the wire.

The acronym LASER stands for

The activity of a radioactive sample is measured as $N_{0}$ counts per minute at $t = 0$ and $N_{0}/e$ counts per minute at $t = 5$ minutes. The time (in minutes) at which the activity reduces to half its value is

The accuracy in the measurement of the diameter of hydrogen atom as $1.06 \times 10^{-10}$ m is

The acceleration due to gravity at the poles and the equator is $g_p$ and $g_e$ respectively. If the earth is a sphere of radius $R_E$ and rotating about its axis with angular speed 0), then $g_p - g_e$ is given by

The absolute zero is the temperature at which -

The $6563 \,?$ $H_\alpha$ line emitted by hydrogen in a star is found to be red-shifted by $15\,?$. The speed with which the star is receding from the earth is