NEET 2013

A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when

The half life of a radioactive isotope 'X' is 20 years. It decays to another element 'Y' which is stable. The two elements 'X' and 'Y' were found to be in the ratio 1 : 7 in a sample of a given rock. The age of the rock is estimated to be

Ratio of longest wave lengths corresponding to Lyman and Balmer series in hydrogen spectrum is

A certain mass of Hydrogen is changed to Helium by the process of fusion. The mass defect in fusion reaction is 0.02866 u. The energy liberated per u is (given 1 u = 931 MeV)

An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 m s\(-\)1 and the second part of mass 2 kg moves with 8 m s\(-\)1 spe...

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 \(\Omega\) is

The resistances of the four arms P, Q, R and S in a Wheatstone's bridge are 10 ohm, 30 ohm, 30 ohm and 90 ohm, respectively. The e.m.f. and internal resistance of the cell are 7 volt and 5 ohm respectively. If the galvanometer resistance is...

A wire of resistance 4 \(\Omega\) is stretched to twice its original length. The resistance of stretched wire would be

A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct ?

For photoelectric emission from certain metal the cutoff frequency is \(\upsilon\). If radiation of frequency 2\(\upsilon\) impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass...

The wavelength \(\lambda\)e of an electron and \(\lambda\)p of a photon of same energy E are related by

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

The condition under which a microwave oven heats up a food item containing water molecules most efficiently is

Two pith balls carrying equal charges are suspended from a common point by strings of equal length, the equilibrium separation between them is r. Now the strings are rigidly clamped at half the height. The equilibrium separation between the...

A, B and C are three points in a uniform electric field. The electric potential is

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

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 cur...

Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1 m, 2 m, 4 m, 8 m, . . . , respectively, from the origin. The resulting gravitational potential due to this system at the origin will be

A body of mass 'm' is taken from the earth's surface to the height equal to twice the radius (R) of the earth. The change in potential energy of body will be

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its temperature. The ratio of \({{{C_p}} \over {{C_p}}}\) for the gas is

The amount of heat energy required to raise the temperature of 1 g of Helium at NTP, from T1K to T2K is

In the given (V \(-\) T) diagram, what is the relation between pressure P1 and P2?

A gas is taken through the cycle
A \(\to\) B \(\to\) C \(\to\) A, as shown. what is the net work done by the gas?

Three blocks with masses m, 2m and 3m are connected by strings, as shown in the figure. After an upward force F is applied on block m, the masses move upwards at constant speed v. What is the net force on the block of mass 2m ? (g is the ac...

The upper half of an inclined plane of inclination \(\theta\) is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between t...

A bar magnet of length \('l'\) and magnetic dipole moment 'M' is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be

A current loop in a magnetic field

The velocity of a projectile at the initial point A is \(\left( {2\widehat i + 3\widehat j} \right)\) m/s. It's velocity (in m/s) at point B is

A stone falls freely under gravity. It covers distances h1, h2 and h3 in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between h1, h2 and h3 is

When a proton is released from rest in a room, it starts with an initial acceleration \(a\)0 towards west. When it is projected towards north with a speed \(v\)0 it moves with an initial acceleration 3\(a\)0 towards west. The an initial acc...

The wettability of a surface by a liquid depends primarily on

The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?

The molar specific heats of an ideal gas at constant pressure and volume are denoted by Cp and Cv, respectively. If  \(\gamma\) = \({{{C_p}} \over {{C_v}}}\) and R is the universal gas constant, then Cv is equal to

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using

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 small object of uniform density rolls up a curved surface with an initial velocity 'v'. It reaches upto a maximum height of \({{3{v^2}} \over {4g}}\) with respect to the initial position. The object is

The output (X) of the logic circuit shown ion figure will be

In a common emitter (CE) amplifier having a voltage gain G, the transistor used has transconductance 0.03 mho and current gain 25. If the above transistor is replaced with another one with transconductance 0.02 mho and current gain 20, the ...

In a n-type semiconductor, which of the following statement is true.

If an experiment four quantities a, b, c and d are measured with percentage error 1%, 2%, 3% and 4% respectively.
Quantity P is calculated as follows P \(= {{{a^3}{b^2}} \over {cd}}\) % error in P is

In Young's double slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths \({\lambda _1}\) = 12000 \(\mathop A\limits^ \circ\) and \({\lambda _2}\) = 10000 \(\mathop A\limits^ \circ\). At what minimum...

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

A source of unknown frequency gives 4 beats/s when sounded with a source of known frquency 250 Hz. The second harmonic of the source of unknown frequency gives five beats per second, when sounded with a source of frequency 513 Hz. The unkno...

If we study the vibration of a pipe open at both ends. then the following statement is not true.

A uniform force of \(\left( {3\widehat i + \widehat j} \right)\) newton acts on a particle of mass 2 kg. Hence the particle is displaced from position \(\left( {2\widehat i + \widehat k} \right)\) metre to position $$\left( {4\widehat i + 3...