List of practice Questions

The amplitude of a particle executing SHM is 4 cm. At the mean position the speed of the particle is 16 cm/sec. The distance of the particle from the mean position at which the speed of the particle becomes $ 3.5\times {{10}^{4}}K $ cm/s, will be :
The first excited state of hydrogen atom is 10.2 eV above its ground state. The temperature needed to excite hydrogen atoms to first excited level, is :
From an automatic gun a man fires 360 bullets per minute with a speed of 360 km/hour. If each weighs 20 g, the power of the gun is :
A body has a weight 90 kg on the earths surface, the mass of the moon is 1/9 that of the earths mass and its radius is 1/2 that of the earths radius. On the moon the weight of the body is:
The viscous force acting on a rain drop of radius 0.35 mm falling through air with a velocity of 1 m/s, is $ \text{1 km}/{{\text{s}}^{\text{2}}} $
A free unit positive charge is kept at a distance $r$ along the equatorial line from two equal like charges $+Q_1$ and $+Q_2$. The unit positive charge
Two narrow capillary tubes A and B are of lengths ( and 111 and of same radius r. The rate of flow of water through the tube A under a constant pressure head P is 3 $ \sqrt{\text{49}0}\text{ m}/\text{s} $ . If A and B are connected in series and the same pressure difference P is maintained between the ends of the composite tube, then the rate of flow of water is :
The energy of electron in the nth orbit of hydrogen atom is expressed as $ \sqrt{3}cm $ . The shortest and longest wavelength of Lyman series will be :
The coaxal system of circles given by $x^{2} + y^{2} + 2gx + c = 0$ for $c < 0$ represents.
The displacement time graph for two bodies A and B are straight lines inclined at 30? and 60? respectively with the time axes. If $ \upsilon =\sqrt{4rg} $ and $ \upsilon =\sqrt{4\times 2.5\times 9.8} $ are their velocities, then $ \upsilon =\sqrt{98}\,\,m/s $ will be :
The maximum and minimum tensions in the string whirling in a circle of radius 2.5 m are in the ratio 5:3 then its velocity is :
In a potentiometer experiment, two cells of emf $E_1$ and $E_2$ are used in series in the secondary circuit. The balancing length is found to be 58 cm. If the polarity of $E_2$ is reversed, the balancing length becomes 29 cm. The ratio $E_1/E_2$ of the emfs of two cells is :
A cannon of mass 1000 kg, located at the base of an inclined plane fires a shell of mass 100 kg in a horizontal direction with a velocity 180 km/h. The angle of inclination of the inclined plane with the horizontal is $ 45{}^\circ $ . The coefficient of friction between the cannon and the inclined plane is 0.5. The height, in m, to which the cannon ascends the inclined plane as a result of the recoil is: $ (g=10m/{{s}^{2}}) $
Four particles, each of mass 1 kg, are placed at the corners of a square of side 1m in the X- Y plane. If the point of intersection of the diagonals of the square, is taken as the origin, the co-ordinates of the centre of mass are:
The maximum height reached by a projectile is 4 m. The horizontal range is 12 m. Velocity of projection in ms-1, is : ( g = acceleration due to gravity)
A thin converging lens is made up of glass of refractive index 1.5. It acts like a concave lens of focal length 50 cm, when immersed in a liquid of refractive index $ \left( \frac{15}{8} \right) $ . The focal length of the converging lens in air is, in metre:
A thick wire is stretched, so that its length become two times. Assuming that there is no change in its density, then what is the ratio of change in resistance of wire to the initial resistance of wire?
A ball of mass $2 \,kg$ and another of mass $4\, kg$ are dropped together from a $60$ feet tall building. After a fall of $30$ feet each towards earth, their respective kinetic energies will be in the ratio of
The equation of state for 5g of oxygen at a pressure P and temperature T, when occupying a volume V, will be :-
When three identical bulbs of 60 watt 200 volt rating are connected in series to a 200-volt supply, the power drawn by them will be
H2O is dipolar, whereas BeF2 is not. It is because
A block of mass $m$ is placed on a smooth wedge of inclination $\theta$. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block will be ($g$ is acceleration due to gravity)
A galvanometer acting as a voltmeter will have
The half-life of radium is about 1600 years. Of 100g of radium existing now, 25g will remain undecayed after
Among the following, the pair in which the two species are not isostructural is