List of practice Questions

Starfish is
A cylindrical lens is required to correct
A cylindrical vessel contains a liquid of density $\rho$ upto a height h. The liquid is closed by a piston of mass m and area of cross section A. There is a small hole at the bottom of the vessel. The speed with which the liquid comes out of the vessel is
A cylindrical vessel of height $500\, mm$ has an orifice (small hole) at its bottom. The orifice is initially closed and water is filled in it upto height $H$. Now the top is completely sealed with a cap and the orifice at the bottom is opened. Some water comes out from the orifice and the water level in the vessel becomes steady with height of water column being $200\, mm$. The fall in height (in mm) of water level due to opening of the orifice is [Take atmospheric pressure $= 1.0 \times10^{5} N/m^{2}$, density of water $= 1000\, kg/m^{3}$ and $g = 10 m/s^{2}$. Neglect any effect of surface tension.]
A dealer wishes to purchase a number of fans and sewing machines. He has only $?\, 5760$ to invest and has space for at most $20$ items. A fan and sewing machine cost $?\, 360$ and $? \,240$ respectively. He can sell a fan at a profit of $?\,22$ and sewing machine at a profit of $? \,18$. Assuming that he can sell whatever he buys, how many fans and sewing machines respectively he sell in order to maximize his profit?
A cyclist moving on a circular track of radius $40\, m$ completes half a revolution in $40 \,s$. Its average velocity is
A cyclotron can be used to produce high energy :
A current of 9.65 ampere flowing for 10 minutes deposits 3.0 g of the metal which is monovalent. The atomic mass of the metal is
A cyclist is riding with a speed of $27\,km\, h^{-1}$. As he approaches a circular turn on the road of radius $80 \,m$, he applies brakes and reduces his speed at the constant rate of $0.50\,m s^{-1}$ every second. The net acceleration of the cyclist on the circular turn is
A current carrying coil is placed in an uniform magnetic field, with its plane parallel to the magnetic field. If the coil turns through angle $\theta$, the torque $\tau$ and $\theta$ are related as :
A current carrying loop of radius r carries a current I. It is placed in a magnetic field $B_0$ such that the plane of the coil is perpendicular to the magnetic field. The net force on the coil is
A cubical vessel of height 1 m is full of water. What is the amount of work done in pumping water out of the vessel? $(Take g = 10 ms^{-2})$
A current carrying circular loop of radius $R$ is placed in the $x - y$ plane with centre at the origin. Half of the loop with $x > 0$ is now bent so that it now lies in the $y - z$ plane
A cricketer can throw a ball to a maximum horizontal distance of $100\,m$. With the same speed how much high above the ground can the cricketer throw the same ball?
A crowbar of length 120 cm has its fulcrum situated at a distance of 20cm from the load. The mechanical advantage of the crow bar is
A cube of wood supporting 200g mass just floats in water. When the mass is removed, the cube rises by 1 cm, the linear dimension of cube is
A cricket ball of mass 0.25 kg with speed 10 ms$^{-1}$ collides with a bat and returns with same speed within 0.01 s. The force acted on bat is
A cricket ball of mass $150\, g$ moving with a speed of $126 \,km/h$ hits at the middle of the bat, held firmly at its position by the batsman. The ball moves straight back to the bowler after hitting the bat. Assuming that collision between ball and bat is completely elastic and the two remain in contact for $0.001\, s$, the force that the batsman had to apply to hold the bat firmly at its place would be
A cricket club has $15$ members of which. only $5$ can bowl. If the names of $15$ members are put into a box and $11$ names are drawn at random, then the probability of obtaining $11$ member team containing exactly three bowlers is
A copper disc of diameter $20\, cm$ makes $1200\, r.p.m$. about its natural axis kept parallel to a uniform magnetic field of $10^{-2}$ T. The potential difference between the centre and edge of the disc is
A cord is wound around the circumference of wheel of radius $r$, the axis of wheel is horizontal and moment of inertia about it is $I$. A weight mg is attached to the cord at the end. The weight falls from rest. After falling through a distance $h$, the angular velocity of wheel will be
A cord of negligible mass is wound round the rim of a flywheel of mass $20 \,kg$ and radius $20\, cm$. A steady pull of $25 \,N$ is applied on the cord. The work done by the pull when $2 \,m$ of the cord is unwound is, if wheel starts from rest, what is the kinetic energy of the wheel when .$2 \,m$ of the cord is unwound?
A cork of mass $10\, g$ is floating on water. The net force acting on the cork is
A convexo-concave lens has faces of radii 3 and 4 cm respectively, and is made of glass of refractive index 1.6, its focal length is
A convex lens of power P is immersed in water. How will its power change ?