List of practice Questions

At what height above the earth?s surface, the value of $g$ is half of its value on earth?s surface? Given its radius is 6400 km.
A horizontal pipe line carries water in a streamline flow. At a point along the pipe where the crosssectional area is 10 cm, the water velocity is 1 ms and the pressure is 2000 Pa. What is the pressure at another point where the crosssectional area is 5 cm?
A frictionless wire AB is fixed on a sphere of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is
Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of 20 cm are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is
Find the position of final image from first lens.If the focal length of each lens is 10 cm.
Which cleansing agent gets precipitated in hard water?
The phenomenon involved in the reflection of radio-waves by ionosphere is similar to
A toroid has 500 turns per metre length. If it carries a current of 2A, the magnetic energy density inside the toroid is
A thermodynamic system undergoes a cyclic process ABC as shown in the diagram. The work done by the system per cycle is
A Point object is moving uniformly towards the pole of a concave mirror of focal length 25 cm along its axis as shown below. The speed of the object is 1 $ms^{-1}$. At t = 0, the distance of the object from the mirror is 50 cm. The average velocity of the image formed by the mirror between time t = 0 and t = 0.25 s is
The brain capacity of Homo habilis
During inelastic collision between two bodies, which of the following quantities always remain conserved?
Ionized hydrogen atoms and $\alpha$-particles with same momenta enters perpendicular to a constant magnetic field. B. The ratio of their radii of their paths $r_H : r_\alpha$ will be :
Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is :
A force F = 20 + 10y action a particle in y-direction where F is in newton and y in meter. Work done by this force to move the particle from y = 0 to y = 1 m is :
When an unpolarised beam of light of intensity $I_0$ is incident on a polaroid, the intensity of transmitted light is
?Lumen? is the unit of
Two beams of red and violet colour are made to pass separately through a prism with angle of prism $60^{\circ}$. In the position of minimum deviation, the angle of refraction will be:
The molecules of which of the following gases has the highest speed?
Which of the following oxides would be reduced by C? ${Al_2 O_3, MgO, ZnO , CaO, Fe_2 O_3 , PbO} $
Let P be a $2 \times 2$ matrix such that [1 0] P = $ - \frac{1}{\sqrt{2}} [ 1 1]$ and $[0 1] P = \frac{1}{\sqrt{2}} [- 1 1]$ . If 0 and I denote the zero and identity matrices of order 2, respectively, then which of the following options is CORRECT ?
Nylon 66 is formed by
In which compound does H show O. N of -1?
The moment of inertia of a disc of mass M and radius R about an axis, which is tangential to the circumference of the disc and parallel to its diameter, is
A body of mass 2 kg thrown vertically upward from the ground with a velocity of $8 \, ms^{-1}$ reaches a maximum height of 3 in. The work done by the air resistance is_______ (Acceleration due to gravity = $10 \, ms^{-2}$)