List of top Physics Questions

Tonoplast is a membrane surrounding the

In an inelastic collision

One end of a horizontal thick copper wire of length $2\, L$ and radius $2 \,R$ is welded to an end of another horizontal thin copper wire of length $L$ and radius $R$. When the arrangement is stretched by applying forces at two ends, the ratio of the elongation in the thin wire to that in the thick wire is

$\lambda_1$ and $\lambda_2$ are used to illuminate the slits. $\beta_1$ and $\beta_2$ are the corresponding fringe widths. The wavelength $\lambda_1$ can produce photoelectric effect when incident on a metal. But the wavelength $\lambda_2$ cannot produce photoelectric effect. The correct relation between $\beta_1$ and $\beta_1$ is

Two satellites $A$ and $B$ go round a planet $P$ in circular orbits having radii $4R$ and $R$ respectively. If the speed of the satellite $A$ is $3\upsilon$, the speed of satellite $B$ will be

The vibrations of a string of length $60\, cm$ fixed at both the ends are represented by the equation $y=2 sin \left(\frac{4\pi x}{15}\right) cos \left(96\pi t\right)$ where $x$ and $y$ are in cm. The maximum number of loops that can be formed in it is

The value of g at a particular point is $9.8 \, ms^{-2}$. Suppose theearth suddenlyshrinks uniformly to half its present size without losing any mass. The value ofg at the same point (distance of the point from the centre of earth does not change) will now be

Particle $A$ moves along the line $ y=4\sqrt{3}\,m $ with constant velocity v of magnitude $2.0 \,m/s$ and directed parallel to the positive $x$ -axis (see figure). Particle $B$ starts at the origin with zero speed and constant accelerationa (of magnitude $ 4.0\,m/s^{2} $ ) at the same instant that the particle A passes the y axis. The angle $ \theta $ between a and the positive $y$ axis that would result in a collision between these two particles should have a value equal to

Which of the following is the best method to reduce eddy currents?

When a slow neutron is captured by a $^{235}_{92} U$ nucleus, a fission energy releasing $200\, MeV$. If power of nuclear reactor is $100\, W$ then rate of nuclear fission is

Velocity of sound waves in air is $330 \,m/s$. For a particular sound in air, a path difference of $40 \,cm$ is equivalent to phase difference of $1.6\pi$ The frequency of the wave is

Two spherical conductors $A$ and $B$ of radii $a$ and $b(b>a)$ are placed concentrically in air. The two arc connected by a copper wire as shown in figure. The equivalent capacitance of the system is

Three thin metal rods, each of mass $M$ and length $L$, are welded to form an equilateral triangle. The moment of inertia of the composite structure about an axis passing through the centre of mass of the structure and perpendicular to its plane is

There are two identical small holes on the opposite sides of a tank containing a liquid. The tank is open at the top. The difference in height between the two holes is $h$. As the liquid comes out of the two holes, the tank will experience a net horizontal force proportional to

The potential difference across the $3 \,\Omega$ resistor shown in figure is

The magnetic flux linked with the coil varies with time as $\phi = 3t^2+4t+9$.The magnitude of the induced emf of $2s$ is

The force $F$ is given by expression $F=A \cos (B x)+C \sin (D t)$, where $x$ is the displacement and $t$ is the time. Then dimension of $\frac{D}{B}$ are same as that of

The energy gap of silicon is $1 .1 4 \,eV$. The maximum wavelength at which silicon starts energy absorption, will be $(h = 6.62 \times 10^{-34}\, J\, s$; $c = 3 \times 10^8\, ms^{ -1})$

The distance between the two successive nodes is

The current passing through an inductor coil of 5H is decreasing at the rate of 2A/s, the emf developed across the coil is

The current and voltage in AC circuit are given by $ I=5\sin \left( 100t-\frac{\pi }{2} \right)A $ and $ V=200\sin (100t) $ volt. The power dissipated in the circuit will be

Polaroid glass is used in sun glasses because

If $x, v$ and $a$ denote the displacement, the velocity and the acceleration of a particle executing simple harmonic motion of time period $T$, then, which of the following does not change with time?

Moment of inertia of a uniform rod of length $L$ and mass $M$, about an axis passing through $L/4$ from one end and perpendicular to its length is

In an intrinsic semiconductor band gap is $1.2\, eV$ then ratio of number of charge carriers at $600\, K$ and $300\, K$ is