List of top Questions asked in NEET (UG)- 2013

A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices $\mu_1$ and $\mu_2$ and $R$ is the radius of curvature of the curved surface of the lenses, then the focal length of combination is

A reaction having equal energies of activation for forward and reverse reactions has :-

A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is:

A sedentary sea anemone gets attached to the shell lining of hermit crab. The association is :

A stone falls freely under gravity. It covers distances $h_1, h_2$ and $h_3$ in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between $h_1, h_2$ and $h_3$ is :-

A uniform force of $(3 \hat{i} + \hat{j})$ newton acts on a particle of mass 2kg. Hence the particle is displaced from position$ (2\hat{i} + \hat{k} )$ meter to position $(4\hat{i} + 3\hat{j} - \hat{k})$ meter. The work done by the force on the particle is :

A wave travelling in the $+ve$ $x-direction$ having displacement along $y$-direction as $1m$, wavelength $2 \pi m$ and frequency of $ \frac{1}{\pi} Hz$ is represented by :

A wire loop is rotated in magnetic field. The frequency of change of direction of the induced e.m.f. is :

A wire of resistance $4 \, \Omega$ is stretched to twice its original length. The resistance of stretched wire would be :

According to Darwin, the organic evolution is due to :

The dissociation constant of a weak acid is $1 \times 10^{-4}$ in order to prepare a buffer solution with a $pH = 5$ the [salt] / [Acid] ratio should be :

Among bitter gourd, mustard, brinjal, pumpkin chinarose, lupin, cucumber, sunnhemp, gram, guava, bean, chilli, plum, petunia, tomato, rose, withania, potato, onion, aloe and tulip how many plants have hypogynous flower ?

Among flowers of Calotropis, tulip, Sesbania, Asparagus, Colchicum, sweet pea, Petunia, Indigofera, mustard, soybean, tobacco and groundnut, how many plants have corolla with valvate aestivation?

At $100^\circ C$ the $K_w$ of water is $55\, times$ its value at $25^\circ C$. What will be the pH of neutral solution ? $(log 55 = 1.74)$

Cell-mediated immunity in the human body is carried out by

How many grams of cobalt metal will be deposited when a solution of cobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (1 Faraday = 96,500 C; Atomic mass of Co = 59 u) :

Dettol is the mixture of :

Dipole induced dipoloe interactions are present in which of the following pairs :-

Down's syndrome in humans is due to

During sewage treatment biogas produced includes

During muscle contraction in humans, the

Eye of Octopus and eye of Cat show different patterns of structure. Yet they perform similar function. This is an example of

For a normal eye, the cornea of eye provides a converging power of $40\, D$ and the least converging power of the eye lens behind the cornea is $20\, D$. Using this information, the distance between the retina and the cornea -eye lens can be estimated to be -

Menstrual flow occurs due to lack of

H-zone in skeletal muscle fibre is due to