List of top Physics Questions

The transverse displacement $y(x, t)$ of a wave on a string is given by $y(x, t)=e^{-\left(a x^{2}+b t^{2}+2 \sqrt{a b} x t\right)}$ This represents a :
A body of mass $5\, kg $ is moving with a momentum of $10\,kg\,m/s $ . A force of $ 0.2\,N $ acts on it in the direction of motion of the body for $10\, s$. The increase in its kinetic energy is
A thin circular ring of mass $ M $ and radius $ r $ is rotating about its axis with constant angular velocity $ \omega $ . Two objects each of mass $ m $ , are placed gently at the opposite ends of diameter of the ring. The ring now rotates with an angular velocity
Two lamps of powers $ {{P}_{1}} $ and $ {{P}_{2}} $ are placed on either side of a paper having an oil spot. The lamps are at distances of 1 m and 2 m respectively on either side of the paper and the oil spot is invisible. What is the value of $ {{P}_{1}}/{{P}_{2}} $ ?
A parallel plate capacitor of value 1.77 $ \mu $ F is to be designed using a dielectric material (dielectric constant = 200), breakdown strength of $ 3\times {{10}^{6}} $ V/m. In order to make such a capacitor which can withstand a potential difference of 20 V across the plates, the separation between the plates d and area A of the plates respectively are
The two waves, whose intensities are $ 9:16 $ are made to interfere. The ratio of maximum and minimum intensities in the interference pattern is
At what temperature is rms speed of air molecules double of that at NTP?
The rate of outflow of liquid through an orifice does not depend upon
On a massless rod four masses are fixed as shown in figure. What is the moment of inertia about an axis passing through centre of rod
A small object placed on a rotating horizontal turn-table just slips when it is placed at a distance of 4 cm from the axis of rotation. If the angular velocity of the turn-table is doubled the object slips when its distance from the axis of rotation is
A bullet moving with speed 200 m/s is just able to pierce a wooden block of 6 cm thickness. What velocity is required to just pierce a block of 8 cm?
What is the relation between particle velocity (v), the wave velocity (c) and the slope (s) of the wave?
A bullet of 5 g is fired with a velocity of 800 m/s. The velocity of bullet becomes 200 m/s when it pierces a wooden block 2 m thick. What is the average resistance offered by the wooden block?
A single slit diffraction pattern is obtained on a screen using 600 nm light when the width of the central (principal) maximum is 0.30 mm. The width of the slit is reduced by 50%. and then illuminated by 450 nm light. Width, in mm, of the central maximum in the second case is;
Which of the following effects could not be observed for sound waves in air ?
A bi-metallic slab is made (refer figure) by fusing two material. The components have same thickness and lengths, but are of thermal conductivities $K_1$ and $K_2$. If the heat were to conduct across the faces $(T_1 > T_2)$, then effective thermal conductivity of the composite slab is
A prism with a refracting angle $30^{\circ}$, made of material of refractive index 1.732, has one of its faces silvered. A ray of light incident at a certain angle on the other face retraces the path after getting reflected at the silvered face. The angle of incidence is
Two trains are moving towards each other with speeds of 20 m/s and 15 m/s relative to the ground. The first train sounds a whistle of frequency 600 Hz, the frequency of the whistle heard by a passenger in the second train before the train meeets is (the speed of sound in air is 340 m/s)
Power supplied to a particle of mass 2 kg varies with time as $ P=\frac{3{{t}^{2}}}{2}W. $ Here t is in second. If velocity of particle at $ t=0 $ is $ v=0, $ the velocity of particle at time $ t=2\,s $ will be
A pulley fixed to the ceiling carries a string with blocks of masses $m$ and $3m$ attached to its ends. The masses of string and pulley are negligible. When the system is released, the acceleration of centre of mass will be
The charge flowing in a conductor varies with time as $ Q=at-b{{t}^{2}}, $ then the current changes at the rate of $ (-2b) $ falls to zero after $ T=\left( \frac{a}{2b} \right) $ (3) reaches a maximum and then decreases (4) will remain constant
A wooden block of mass $M$ resting on a rough horizontal surface is pulled with a force $F$ at an angle with the horizontal. If $ \mu $ is the coefficient of kinetic friction between the block and the surface, then acceleration of the block is
The work done by an applied variable force $F=x +x^{3}$ from $x=o m$ to $x=2, m$ where $x$ is displacement, is
In a stationary wave all the particies
The reduced mass of two particles having masses $m$ and $2\, m$ is