List of top Physics Questions

A particle of mass ' \(m\) ' is executing S.H.M. about the origin on \(x\)-axis with frequency \(\sqrt{\frac{ka}{\pi m}}\), where ' \(k\) ' is a constant and ' \(a\) ' is the amplitude of S.H.M. If ' \(x\) ' is a displacement of a particle, at time ' \(t\) ', potential energy of the particle will be
A pipe closed at one end vibrating in fifth overtone is in unison with open pipe vibrating in its fifth overtone. The ratio of \(l_c : l_o\) is [\(l_c = \text{vibrating length of closed pipe}, l_o = \text{vibrating length of open pipe}\)]
Two stars 'A' and 'B' radiate maximum energy at \(5200\text{ \AA}\) and \(6500\text{ \AA}\) respectively. Then the ratio of absolute temperatures of stars ' A ' and ' B ' is
The resistance of a coil for d.c. is \(5\Omega\). In a.c., the resistance will
A hollow charged metal sphere has a radius ' \(r\) '. If the potential difference between its surface and a point at a distance ' \(3r\) ' from the centre is ' \(v\) ', then the electric field intensity at a distance ' \(3r\) ' is
When a ray of light is refracted from one medium to another, then the wavelength changes from \(6000\text{ \AA}\) to \(4000\text{ \AA}\). The critical angle for the interface will be
In between the plates of parallel plate capacitor of plate separation '$d$' a dielectric plate of thickness '$t$' is inserted. The capacitance becomes one-third of the original capacity without dielectric. The dielectric constant of the plate is
A thin rod of length ' $4L$ ' and mass ' $4m$ ' is bent as shown. Find the moment of inertia about an axis through $O$ and perpendicular to the plane.
Two different coils have self - inductance \(L_1 = 9\text{ mH}\) and \(L_2 = 3\text{ mH}\). The current in first coil is increased at a constant rate. The current in the second coil is also increased at the same constant rate. At certain instant of time, the power given to the two coils is same. At that time, there was current and induced voltage in the two coils. At the same instant, the ratio of the energy stored in the first coil to that in second coil is
Water is flowing through a horizontal pipe in a streamline flow. At the narrowest part of the pipe
Four masses of \(1\text{ kg}, 2\text{ kg}, 3\text{ kg}\) and \(4\text{ kg}\) are kept at co-ordinates \((0, 0)\text{m, (0, 1)\text{m}\) and \((1, 0)\text{m}\) respectively. Using the co-ordinates of centre of mass its position vector is}
If the angular momentum of a particle of mass $m$ rotating along a circular path of radius $r$ with uniform speed is L, the centripetal force acting on the particle is
Two discs rotating about their respective axis of rotation with angular speeds $2 \text{ rads}^{-1}$ and $5 \text{ rads}^{-1}$ are brought into contact such that their axes of rotation coincide. Now, the angular speed of the system becomes $4 \text{ rads}^{-1}$. If the moment of inertia of the second disc is $1 \times 10^{-3} \text{ kg m}^2$, then the moment of inertia of the first disc (in $\text{kg m}^2$) is}
A wheel is rotating at 1800 rpm about its own axis. When the power is switched off, it comes to rest in 2 minutes. Then the angular retardation in $\text{rad s}^{-2}$ is}
Pick out the wrong statement from the following
Two blocks of masses 2 kg and 4 kg are attached by an inextensible light string as shown in the figure. If a force of 120 N pulls the blocks vertically upward, the tension in the string is (take \(g = 10 \text{ ms}^{-2}\))
A cyclist bends while taking turn in order to
In elastic collision
The total energy of a solid sphere of mass 300 g which rolls without slipping with a constant velocity of 5 ms\(^{-1}\) along a straight line is
A bullet when fired into a target loses half of its velocity after penetrating 20 cm. Further distance of penetration before it comes to rest is
The vertical component of velocity of a projectile at its maximum height ($u$ – velocity of projection, $\theta$ – angle of projection) is
A particle has the position vector $\vec{r} = \hat{i} - 2\hat{j} + \hat{k}$ and the linear momentum $\vec{p} = 2\hat{i} - \hat{j} + \hat{k}$. Its angular momentum about the origin is}
A particle starting with certain initial velocity and uniform acceleration covers a distance of 12 m in first 3 seconds and a distance of 30 m in next 3 seconds. The initial velocity of the particle is
The coordinates of a particle moving in $x-y$ plane at any instant of time $t$ are $x = 4t^2$; $y = 3t^2$. The speed of the particle at that instant is
A ball of mass 10 g moving perpendicular to the plane of the wall strikes it and rebounds in the same line with the same velocity. If the impulse experienced by the wall is 0.54 Ns, the velocity of the ball is