AIPMT 2006

A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of frequency \(f\). If L is doubled and C is changed to 4C, the frequency will be

The core of a transformer is laminated because

A coil of inductive reactance 31 \(\Omega\) has a resistance of 8 \(\Omega\). It is placed in series with a condenser of capacitative reactance 25 \(\Omega\). The combination is connected to an a.c. source of 110 V. The power factor of t...

Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emited by hydrogen will be

In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is \(\lambda\), then

The radius of germanium (Ge) nuclide is measured to be twice the radius of \({}_4^9\)Be. The number of nucleons in Ge are

The binding energy of deuteron is 2.2 MeV and that of \({}_2^4\)He is 28 MeV. If two deuterons are fused to form one \({}_2^4\)He then the energy released is

A parallel plate air capacitor is charged to a potential difference of V volts. After disconnecting the charging battery the distance between the plates of the capacitor is increased using an insulting handle. As a result the potential diff...

A 0.5 kg ball moving with a speed of 12 m/s strikes a hand wall at an angle of 30o with the wall. It is reflected with the same speed at the same angle. If the ball is in contact with the wall for 0.25 seconds, the average force acting on t...

Kirchoff's first and second laws of electrical circuits are consequences of

Two cells, having the same e.m.f. are connected in series through an external resistance R. Cells have internal resistances r1 and r2 (r1 > r2) respectively. When the circuit is closed, the potential difference across the first cell is zero...

In the circuit shown, if a conducting wire is connected between points A and B, the current in this wire will

Power dissipated across the 8 \(\Omega\) resistor in the circuit shown here is 2 watt. The power dissipated in watt units across the 3 \(\Omega\) resistor is

The momentum of a photon of energy 1 MeV in kg m/s will be

When photons of energy h\(\upsilon\) fall on an aluminimum plate (of work function E0), photoelectrons of maximum kinetic energy K are ejected. If the frequency of radiation is doubled, the maximum kinetic energy of the ejected photoelectr...

In a discharge tube ionization of enclosed gas is produced due to collisions between

A photocell employs photoelectric effect to convert

Two coils of self inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is

An electric dipole of moment \(\overrightarrow p\) is lying along a uniform electric field \(\overrightarrow E\). The work done in rotating the dipole by 90o is

A square surface of side L metres is in the plane of the paper. A uniform electric field \(\overrightarrow E\) (volt/m), also in the plane of the paper is limited only to the lower half of the square surface (see figure). The electric flux...

A convex lens and a concave lens, each having same focal length of 25 cm, are put in contact to form a combination of lenses. The power in diopters of the combination is

A microscope is focussed on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again ?

The earth is assumed to be a sphere of radius R. A platform is arranged at a height R from the surface of the earth. The escape velocity of a body from this platform is fv, where v is its escape velocity from the surface of the Earth. The ...

The molar specific heat at constant pressure of an ideal gas is (7/2) R. The ratio of specific heat at constant pressure to that at constant volume is

A Carnot engine whose sink is at 300 K has an efficiency of 40%. By how much should the temperature of source be increased so as to increase its efficiency by 50% of original efficiency ?

Curie temperature above which

For angles of projection of a projectile at angle (45o \(-\) \(\theta\)) and (45o + \(\theta\)), the horizontal range described by the projectile are in the ratio of

The vectors \(\overrightarrow A\) and \(\overrightarrow B\) are such that \(\left| {\overrightarrow A + \overrightarrow B } \right| = \left| {\overrightarrow A - \overrightarrow B } \right|.\) The angle between the two vectors is

Two bodies A (of mass 1 kg) and B (of mass 3 kg) are dropped from heights of 16 m and 25 m, respectively. The ratio of the time taken by them to reach the ground is

A particle moves along a straight line OX. At a time t (in seconds) the distance x (in metres) of the particle from O is given by x = 40 + 12t \(-\) t3. How long would the particle travel before coming to rest ?

A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 seconds for every circular lap. The average velocity and average speed for each circular lap respectively is

When a charged particle moving with velocity \(\overrightarrow v\) is subjected to a magnetic field of induction \(\overrightarrow B\), the force on it is non-zero. This implies that

Two circular coils 1 and 2 are made from the same wire but the radius of the 1st coil is twice that of the 2nd coil. What is the ratio of potential difference in volts should be applied across them so that the magnetic field at their centre...

A rectangular block of mass m and area of cross-section A floats in a liquid of density \(\rho\). If it is given a small vertical displacement from equilibrium it undergoes with a time period T, then

A black body at 1227oC emits radiations with maximum intensity at a wavelength of 5000 \(\mathop A\limits^ \circ\). If the temperature of the body is increased by 1000oC, the maximum intensity will be observed at

A tube of length L is filled completely with an incompressible liquid of mass M and closed at both the ends. The tube is then rotated in a horizontal plane about one of its ends with a uniform angular velocity \(\omega\). The force exerte...

The moment of inertia of a uniform circular disc of radius R and mass M about an axis touching the disc at its diameter and normal to the disc

A uniform rod AB of length \(l\) and mass m is free to rotate about point A. The rod is released from rest in the horizontal position. Given that the moment of inertia of the rod about A is ml2/3, the initial angular acceleration of the rod...

A transistor is operated in common emitter configuration at constant collector voltage VC = 1.5 V such that a change in the base current from 100 \(\mu\)A to 150 \(\mu\)A profuces a change in the collector current from 5 mA to 10 mA. The ...

Which one of the following represents forward bias diode ?

The following figure shows a logic gate circuit with two inputs A and B and the output C.

The voltage waveforms of A, B and C are as shown below.

The logic circuit gate is

The velocity v of a particle at time t is given by v = at + \({b \over {t + c}}\), where a, b and c are constants. The dimensions of a, b and c are

Two sound waves with wavelengths 5.0 m and 5.5. m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats per second.

Two vibrating tuning forks produce waves given by y1 = 4 sin 500\(\pi\)t and y2 = 2 sin506 \(\pi\)t. Number of beats produced per minute is

The time of reverberation of a room A is one second. What will be the time (in seconds of reverberation of a room, having all the dimensions double of those of room A ?

A transverse wave propagating along x-axis is represented by y(x, t) = 8.0 sin (0.5 \(\pi\)x \(-\) 4\(\pi\)t \(-\) \(\pi\)/4) where x is in metres and t is in seconds. The speed of the wave is

Which one of the following statements is true ?

A body of mass 3 kg is under a constant force which causes a displacement s in metres in it, given by the relation s = \({1 \over 3}\)t2, where t is in seconds. Work done by the force in 2 seconds is

The potential energy of a long spring when stretched by 2 cm is U. If the spring is stretched by 8 cm the potential energy stored in it is

300 J of work is done in sliding a 2 kg block up an inclined plane of height 10 m. Work done against friction is (Take g = 10 m/s2)