Official NEET UG 2014

If force (F), velocity (V) and time (T) are taken as fundamental units, then the dimensions of mass are:-

A projectile is fired from the surface of the earth with a velocity of \(5 ms^{–1}\) and angle \(\theta\) with the horizontal. Another projectile fired from another planet with a velocity of \(3 ms^{–1}\) at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in \( ms^{–2}\)) given \(g = 9.8 m/s^{2}\)

A particle is moving such that its position coordinate (x, y) are

(2m, 3m) at time t = 0

(6m, 7m) at time t = 2 s and

(13m, 14m) at time t = 5s.

Average velocity vector \(( \overrightarrow{V}_{av} )\) from t = 0 to t = 5 s is :-

A system consists of three masses \(m_{1}, m_{2}\) and \(m_{3}\) connected by a string passing over a pulley P. The mass \(m_{1}\) hangs freely and \(m_{2}\) and \(m_{3}\) are on a rough horizontal table (the coefficient of friction = \(\mu \)). The pulley is frictionless and of negligible mass. The downward acceleration of mass \(m_{1}\) is : (Assume \(m_{1} = m_{2} = m_{3} = m\))

The force ‘F’ acting on a particle of mass ‘m’ is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is :-

A balloon with mass ‘m’ is descending down with an acceleration ‘a’ (where a < g). How much mass should be removed from it so that it starts moving up with an acceleration ‘a’ ?

A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (v). The total kinetic energy generated due to explosion is :-

The oscillation of a body on a smooth horizontal surface is represented by the equation,

\(X = A cos(\omega t) \)

where   X = displacement at time t
\(\omega \)= frequency of oscillation
Which one of the following graphs shows correctly the variation ‘a’ with ‘t’ ?

A solid cylinder of mass 50 kg and radius 0.5 m is free to rotate about the horizontal axis. A massless string is wound round the cylinder with one end attached to it and other hanging freely. Tension in the string required to produce an angular acceleration of 2 revolutions \(s^{–2}\) is :-

The ratio of the accelerations for a soldi sphere (mass ‘m’ and radius ‘R’) rolling down an incline of angle ‘\(\theta \)’ without slipping and slipping down the incline without rolling is :-

A black hole is an object whose gravitational field is so strong that even light cannot escape from it. To what approximate radius would earth (mass = \(5.98 \times 10^{24}kg\)) have to be compressed to be a black hole ?

Dependence of intensity of gravitational field (E) of earth with distance (r) from centre of earth is correctly represented by :-

Copper of fixed volume ‘V; is drawn into wire of length ‘l’. When this wire is subjected to a constant force ‘F’, the extension produced in the wire is ‘\(\Delta l\)’. Which of the following graphs is a straight line ?

A certain number of sphereical drops of a liquid of radius ‘r’ coalesce to form a single drop of radius ‘R’ and volume ‘V’. If ‘T’ is the surface tension of the liquid, then :