List of top Physics Questions

The wavelength of red light from $He-Ne$ laser is $ 633\, nm $ in air but $ 474 $ nm in the aqueous humor inside the eye ball. Then the speed of red light through the aqueous humor is
The velocity of electromagnetic radiation in a medium of permittivity ? and permeability � is given by
The unit of universal gas constant is
The forbidden gap in the energy bands of silicon is
The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the
The image formed by a concave mirror
If two molecules of $A$ and $B$ having mass $100 \,kg$ and $64\, kg$ and rate of diffusion of $A$ is $ 12\times 10^{-3}, $ then what will be the rate of diffusion of $B$?
In radioactive decay process, the negatively charged emitted (3-particles are
The mass of the earth is $6 \times 10^{24}\, kg$ and that of the moon is $7.4 \times 10^{22}\, kg$. The potential energy of the system is $-7.79 \times 10^{28}\, J$. The mean distance between the earth and moon is $(G = 6.67 \times 10^{-11}\, N\, m^2kg^{-2})$
Spherical balls of radius R are falling in a viscous fluid of viscosity $ \eta $ with a velocity v. The retarding viscous force acting on the spherical ball is
A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement $ x $ is proportional to
What is X in the following nuclear reaction? ${ }_{7} N ^{14}+{ }_{1} H ^{1} \longrightarrow{ }_{8} O ^{15}+X$
If the lattice constant of this semiconductor is decreased, then which of the following is correct ? Conduction band width Band gap Valence band width
Consider a two particle system with particles having masses m, and m2. If the first particle is pushed towards the centre of mass through a distance d, by what distance should the second particle be moved, so as to keep the centre of mass at the same position ?
A thin circular ring of mass m and radius R is rotating about its axis with a constant angular velocity $\omega.$Two objects each of mass M are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with an angular velocity $\omega.$' = :
When white light passes through a prism, the deviation is maximum for
Two sound waves with wavelength $5.0 \,m$ and $5.5 \,m$ respectively, each propagate in a gas with velocity $330 \,m/s$. We expect the following number of beats per second
Two particles of equal charges after being accelerated through the same potential difference enter a uniform transverse magnetic field and describe circular path of radii $ {{R}_{1}} $ and $ {{R}_{2}} $ respectively. Then the ratio of their masses $ ({{M}_{1}}/{{M}_{2}}) $ is
Two heater wires, made of the same material and having the same length and the same radius, are first connected in series and then in parallel to a constant potential difference. If the rates of heat produced in the two cases are $H_s$ and $H_p$ respectively, then $H_s /H_p$ will be
Three point charges $+q,-2 q$ and $+q$ are placed at points $(x=0, y=a, z=0),(x=0, y=0, z=0)$ and $(x=a, y=0, z=0)$, respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are
Three charges $ {{Q}_{0}},-q $ and $ -q $ are placed at the vertices of an isosceles right angle triangle as in the figure. The net electrostatic potential energy is zero if $ {{Q}_{0}} $ is equal to
The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be
The refractive index of glass is 1.520 for red light and 1.525 for blue light. Let $ \quad D_{1}$ and $ \quad D_{2}$ be angles of minimum deviation for red and blue light respectively in a prism of this glass, then,:
The potential energy of a 1 kg particle free to move along the x-axis is given by $V \left(x\right)=\left(\frac{x^{4}}{4}-\frac{x^{2}}{2}\right) J\cdot$ The total mechanical energy of the particle is 2 J. Then , the maximum speed (in m/s) is :
The plates of a parallel plate capacitor are not. exactly parallel. The surface charge density