List of top Physics Questions

The direction of ray of light incident on a concave mirror is shown by $PQ$ while directions in which the ray would travel after reflection is shown by four rays marked $1, 2, 3$ and $4$. Which of the four rays correctly shows the direction of reflected ray?
The direction of magnetic lines of force of a bar magnet is
The dimensions of the emf of a source of current are that of
The dimensions of ( velocity )$^2$ /radius are the same as that of
The dimensional formula for pressure gradient is
The dimensional formula for strain energy density is
The dimensions of (force constant + mass)$^{1/2}$ are the same as that of
The dimensional formula for amplitude of SHM is:
The dimensional formula for Magnetic induction is
The dimensional formula for magnetic moment is
The dimensional formula for Magnetic Moment of a magent is
The dimensional formula for acceleration, velocity and length are $a?^{-2}, \,a?^{-1}$ and $\alpha\gamma$. What is the dimensional formula for the coefficient of friction ?
The dielectric strength of air is $2.0\times10^6 N/C$. The largest charge that a metallic sphere of $3 \,mm$ radius can hold is
The dielectric strength of a medium is $2\,kVmm^{-1}$ . What is the maximum potential difference that can be set up across a $50\,pm$ specimen without puncturing it.
The diameter of the pupil of human eye is about $2 \,mm$. Human eye is most sensitive to the wavelength of $555\, nm$. The limit of resolution of human eye is
The device which produces highly coherent sources is
The density of water at the surface of the ocean is $\rho$ and atmospheric pressure is $p _{0}$. If the bulk modulus of water is $K$, what is the density of ocean water at a depth where the pressure is $n p_{0}$ ?
The density of air at N.T.P. is 1.293 gm/lit. If the pressure is tripled keeping its temperature constant its density becomes
The density of core of a planet is $\rho_1$ and that of the outer shell is $\rho_2$. The radii of core and that of the planet are $R$ and $2R$ respectively. Gravitational acceleration at the surface of planet is same as at a depth. The ratio between $\frac{\rho _{1}}{\rho _{2}}$ is
The definition of current gain is given by
The de Broglie Wavelength of a molecule of thermal energy KT (K is Boltzmann constant. and T is absolute temperature) is given by
The de Broglie wavelength of a photon is twice the de Broglie wavelength of an electron. The speed of the electron is $v_{e}=\frac{c}{100}$ then
The decay constant of radium is $ 4.28 \times 10^{-4} $ per yr .Its half-life is approximately
The current passing through a choke coil of 15 henry is decreasing at the rate of 0.2 ampere per second. The e.m.f. developed across the coil :
The current amplification factor $\alpha$ of a common base transistor and the current amplification factor $\beta$ of a common emitter transistor are not related by