Neet 2005 PYQ Free Mock Test

For skywave propagation of a $10\text{MHz}$ signal, what should be the minimum electron density in the ionosphere?

Which of the following logic gates is an universal gate?

What should be the maximum acceptance angle at the air-core interface of an optical fibre if $n_1$ and $n_2$ are the refractive indices of the core and the cladding, respectively?

A conducting ring of radius $1\text{meter}$ is placed in a uniform magnetic field $B$ of $0.01\text{tesla}$ oscillating with frequency $100\text{Hz}$ with its plane at right angles to $B$. What will be the induced electric field?

Consider an $n$ -$p$ -$n$ transistor amplifier in common-emitter configuration. The current gain of the transistor is $100$. If the collector current changes by $1\text{mA}$, what will be the change in emitter current?

A telescope has an objective lens of focal length $200\text{cm}$ and an eye piece with focal length $2\text{cm}$. If this telescope is used to see a $50\text{meter}$ tall building at a distance of $2\text{km}$, what is the height of the image of the building formed by the objective lens?

The ground state energy of hydrogen atom is $-13.6\text{eV}$. What is the potential energy of the electron in this state?

Solid targets of different elements are bombarded by highly energetic electron beams. The frequency ($f$) of the characteristic X-rays emitted from different targets varies with atomic number $Z$ as:

Two infinitely long parallel conducting plates having surface charge densities $+\sigma$ and $-\sigma$ respectively, are separated by a small distance. The medium between the plates is vacuum. If ${\epsilon }_0$ is the dielectric permittivity of vacuum, then the electric field in the region between the plates is:

In a semiconducting material the mobilities of electrons and holes are ${\mu }_e$ and ${\mu }_h$ respectively. Which of the following is true?

The magnetic moment $(\mu )$ of a revolving electron around the nucleus varies with principal quantum number $n$ as:

A radioactive material has a half-life of $10\text{days}$. What fraction of the material would remain after $30\text{days}$?

According to Hubble's law, the redshift ($Z$) of a receding galaxy and its distance $r$ from earth are related as:

When exposed to sunlight, thin films of oil on water often exhibit brilliant colours due to the phenomenon of:

"Parsec" is the unit of:

The voltage gain of the following amplifier is:

A $50\text{Hz}$ a.c. source of $20\text{volts}$ is connected across $R$ and $C$ as shown in figure. The voltage across $R$ is $12\text{volt}$. The voltage across $C$ is:

In the figure given, the position-time graph of a particle of mass $0.1\text{kg}$ is shown. The impulse at $t=2\text{sec}$ is:

The pressure exerted by an electromagnetic wave of intensity $I({\text{watt/m}}^2)$ on a nonreflecting surface is [$c$ is the velocity of light]:

A block of mass $10\text{kg}$ is moving in $x$ -direction with a constant speed of $10\text{m/sec}$. It is subjected to a retarding force $F=-0.1x\text{joule/meter}$ during its travel from $x=20\text{meter}$ to $x=30\text{meter}$. Its final kinetic energy will be:

Energy required to break one bond in $\text{DNA}$ is approximately:

The condition for a uniform spherical mass $m$ of radius $r$ to be a black hole is [$G=\text{gravitational constant}$ and $c=\text{speed of light}$ ]:

Which of the following is an amorphous solid?

For a constant hydraulic stress on an object, the fractional change in the object's volume $(\Delta V/V)$ and its bulk modulus ($B$) are related as:

Which of the following functions represents a simple harmonic oscillation?

In case of linearly polarised light, the magnitude of the electric field vector:

The circuit shown below acts as:

For ensuring dissipation of same energy in all three resistors ($R_1,R_2,R_3$) connected as shown in figure, their values must be related as:

The apparent depth of water in cylindrical water tank of diameter $2R\text{cm}$ is reducing at the rate of $x\text{cm/minute}$ when water is being drained out at a constant rate. The amount of water drained in $\text{c.c.}$ per minute is ($n_1=\text{refractive index of air}$, $n_2=\text{refractive index of water}$):

A candle of diameter $d$ is floating on a liquid in a cylindrical container of diameter $D(D>>d)$ as shown in figure. If it is burning at the rate of $2\text{cm/hour}$ then the top of the candle will:

A given shaped glass tube having uniform cross section is filled with water and is mounted on a rotatable shaft as shown in figure. If the tube is rotated with a constant angular velocity $\omega$ then:

When a ball is thrown up vertically with velocity $v_0$, it reaches a maximum height of $h$. If one wishes to triple the maximum height then the ball should be thrown with velocity:

A solid sphere is rolling on a frictionless surface, shown in figure with a translational velocity $v\text{m/s}$. If it is to climb the inclined surface then $v$ should be:

A horizontal platform is rotating with uniform angular velocity around the vertical axis passing through its centre. At some instant of time a viscous fluid of mass $m$ is dropped at the centre and is allowed to spread out and finally fall. The angular velocity during this period:

A ladder is leaned against a smooth wall and it is allowed to slip on a frictionless floor. Which figure represents trace of its centre of mass?

A person is standing in an elevator. In which situation he finds his weight less?

A magnet is made to oscillate with a particular frequency, passing through a coil as shown in figure. The time variation of the magnitude of e.m.f. generated across the coil during one cycle is:

Two concentric conducting thin spherical shells $A$ and $B$ having radii $r_A$ and $r_B$ ($r_B>r_A$) are charged to $Q_A$ and $-Q_B$ ($|Q_B|>|Q_A|$). The electrical field along a line (passing through the centre) is:

Dimension of electrical resistance is:

Four point $+ve$ charges of same magnitude ($Q$) are placed at four corners of a rigid square frame as shown in figure. The plane of the frame is perpendicular to $Z$ -axis. If a $-ve$ point charge is placed at a distance $z$ away from the above frame ($z\ll L$) then:

Assertion: Specific gravity of a fluid is a dimensionless quantity.Reason: It is the ratio of density of fluid to the density of water.

Assertion: Frictional forces are conservative forces.Reason: Potential energy can be associated with frictional forces.

Assertion: By roughening the surface of a glass sheet its transparency can be reduced.Reason: Glass sheet with rough surface absorbs more light.

Assertion: A diode lasers are used as optical sources in optical communication.Reason: Diode lasers consume less energy.

Assertion: Diamond glitters brilliantly.Reason: Diamond does not absorb sunlight.

Assertion: The energy ($E$) and momentum ($p$) of a photon are related by $p=E/c$.Reason: The photon behaves like a particle.

Assertion: The clouds in sky generally appear to be whitish.Reason: Diffraction due to clouds is efficient in equal measure at all wavelengths.

Assertion: Television signals are received through sky-wave propagation.Reason: The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency.

Assertion: The logic gate NOT can be built using diode.Reason: The output voltage and the input voltage of the diode have $180^{\circ }$ phase difference.

Assertion: The resolving power of a telescope is more if the diameter of the objective lens is more.Reason: Objective lens of large diameter collects more light.

Assertion: Reversible systems are difficult to find in real world.Reason: Most processes are dissipative in nature.

Assertion: For a system of particles under central force field, the total angular momentum is conserved.Reason: The torque acting on such a system is zero.

Assertion: Air quickly leaking out of a balloon becomes cooler.Reason: The leaking air undergoes adiabatic expansion.

Assertion: It is not possible to use ${}^{35}\text{Cl}$ as the fuel for fusion energy.Reason: The binding energy of ${}^{35}\text{Cl}$ is too small.

Assertion: The number of electrons in a $p$ -type silicon semiconductor is less than the number of electrons in a pure silicon semiconductor at room temperature.Reason: It is due to law of mass action.

Assertion: In a common emitter transistor amplifier the input current is much less than the output current.Reason: The common emitter transistor amplifier has very high input impedance.

Assertion: A body that is a good radiator is also a good absorber of radiation at a given wavelength.Reason: According to Kirchhoff's law the absorptivity of a body is equal to its emissivity at a given wavelength.

Assertion: In pressure-temperature ($P$ -$T$) phase diagram of water, the slope of the melting curve is found to be negative.Reason: Ice contracts on melting to water.

Assertion: For higher temperatures the peak emission wavelength of a black body shifts to lower wavelengths.Reason: Peak emission wavelengths of a blackbody is proportional to the fourth-power of temperature.

Assertion: For Reynold number $R_e>2000$, the flow of fluid is turbulent.Reason: Inertial forces are dominant compared to the viscous forces at such high Reynold numbers.

Among the following molecules(i) ${\text{XeO}}_3$ (ii) ${\text{XeOF}}_4$ (iii) ${\text{XeF}}_6$ Those having same number of lone pairs on $\text{Xe}$ are:

An aqueous solution of ${\text{CoCl}}_2$ on addition of excess of concentrated $\text{HCl}$ turns blue due to formation of:

In which of the following pairs both the complex's show optical isomerism?

The diamagnetic species is:

In the balanced chemical reaction${\text{IO}}_3^{-}+a{\text{I}}^{-}+b{\text{H}}^{+}\to c{\text{H}}_2\text{O}+d{\text{I}}_2$$a,b,c$ and $d$ respectively corresponds to:

Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other, in:

The number of $\text{P}-\text{O}-\text{P}$ bridges in the structure of phosphorus pentoxide and phosphorus trioxide are respectively:

In diborane, the two $\text{H}-\text{B}-\text{H}$ angles are nearly:

Which of the following gives propyne on hydrolysis?

The pair of amphoteric hydroxides is:

Which of the following is a carbonate ore?

${}_{92}^{238}\text{U}$ emits $8$ $\alpha$ -particles and $6$ $\beta$ -particles. The neutron/proton ratio in the product nucleus is:

The correct order for the wavelength of absorption in the visible region is:

${\text{F}}_2$ formed by reacting ${\text{K}}_2{\text{MnF}}_6$ with:

The isoelectronic pair is:

Which of the following chemicals are used to manufacture methyl isocyanate that caused "Bhopal Tragedy"?(i) methylamine(ii) phosgene(iii) phosphine(iv) dimethylamine

$\alpha$ -Particles can be detected using:

Which of the following molecules is most suitable to disperse benzene in water?

The chemical reaction, $2{\text{AgCl}}_{(s)}+{\text{H}}_{2(g)}\to 2{\text{HCl}}_{(aq)}+2{\text{Ag}}_{(s)}$ taking place in a galvanic cell is represented by the notation:

If $Z$ is the number of atoms in the unit cell that represents the closest packing sequence ... $ABCABC$ ..., the number of tetrahedral voids in the unit cell is equal to:

$\Delta H_f^{\circ }(298\text{K})$ of methanol is given by the chemical equation:

An endothermic reaction with high activation energy for the forward reaction is given by the diagram:

When $10\text{ml}$ of $0.1\text{M}$ acetic acid ($p{K}_a=5.0$) is titrated against $10\text{ml}$ of $0.1\text{M}$ ammonia solution ($p{K}_b=5.0$), the equivalence point occurs at $pH$:

The most probable radius (in $\text{pm}$) for finding the electron in ${\text{He}}^{+}$ is:

For the reaction of one mole of zinc dust with one mole of sulphuric acid in a bomb calorimeter, $\Delta U$ and $w$ corresponds to:

For reaction $aA\to xP$, when $[A]=2.2\text{mM}$, the rate was found to be $2.4{\text{mM s}}^{-1}$. On reducing concentration of $A$ to half, the rate changes to $0.6{\text{mM s}}^{-1}$. The order of reaction with respect to $A$ is:

For reaction, $2{\text{NOCl}}_{(g)}\rightleftharpoons 2{\text{NO}}_{(g)}+{\text{Cl}}_{2(g)}$, $K_c$ at $427^{\circ }\text{C}$ is $3\times 10^{-6}{\text{L mol}}^{-1}$. The value of $K_p$ is nearly:

For the chemical equilibrium, ${\text{CaCO}}_{3(s)}\rightleftharpoons {\text{CaO}}_{(s)}+{\text{CO}}_{2(g)}$, $\Delta H_r^{\circ }$ can be determined from which one of the following plots?

Among the following the strongest nucleophile is:

The major product formed in the following reaction is:

The major product obtained on treatment of ${\text{CH}}_3{\text{CH}}_2{\text{CH(F)CH}}_3$ with ${\text{CH}}_3{\text{O}}^{-}/{\text{CH}}_3\text{OH}$ is:

Among the following the most stable compound is:

3-Phenylpropene on reaction with $\text{HBr}$ gives (as a major product):

${\text{CH}}_3{\text{CO}}_2{\text{C}}_2{\text{H}}_5$ on reaction with sodium ethoxide in ethanol gives $A$, which on heating in the presence of acid gives $B$. Compound $B$ is:

Among the following which one does not act as an intermediate in Hofmann rearrangement?

Pyridine is less basic than triethylamine because:

Which one of the following biomolecules is insoluble in water?

Correct configuration of the following is:

Which one of the following statements is true for protein synthesis (translation)?

${\text{C}}_6{\text{H}}_5{\text{CONHCH}}_3$ can be converted into ${\text{C}}_6{\text{H}}_5{\text{CH}}_2{\text{NHCH}}_3$ by:

Assertion : Reaction of ${\text{SO}}_2$ and ${\text{H}}_2\text{S}$ in the presence of ${\text{Fe}}_2{\text{O}}_3$ catalyst gives elemental sulphur.Reason : ${\text{SO}}_2$ is a reducing agent.

Assertion : ${\text{SiF}}_6^{2-}$ is known but ${\text{SiCl}}_6^{2-}$ is not.Reason : Size of fluorine is small and its lone pair of electrons interacts with $d$ -orbitals of $\text{Si}$ strongly.

Assertion : Borax bead test is not suitable for $\text{Al(III)}$.Reason : ${\text{Al}}_2{\text{O}}_3$ is insoluble in water.

Assertion : Ozone is a powerful oxidising agent in comparison to ${\text{O}}_2$.Reason : Ozone is diamagnetic but ${\text{O}}_2$ is paramagnetic.

Assertion : Potassium ferrocyanide is diamagnetic whereas potassium ferricyanide is paramagnetic.Reason : Crystal field splitting in ferrocyanide ion is greater than that of ferricyanide ion.

Assertion : Addition of ${\text{NH}}_4\text{OH}$ to an aqueous solution of ${\text{BaCl}}_2$ in the presence of ${\text{NH}}_4\text{Cl}$ (excess) precipitates $\text{Ba}(\text{OH}{)}_2$.Reason : $\text{Ba}(\text{OH}{)}_2$ is insoluble in water.

Assertion : ${\text{SeCl}}_4$ does not have a tetrahedral structure.Reason : $\text{Se}$ in ${\text{SeCl}}_4$ has two lone pairs.

Assertion : The molecular weight of acetic acid determined by depression in freezing point method in benzene and water was found to be different.Reason : Water is polar and benzene is non-polar.

Assertion : Compressibility factor for hydrogen varies with pressure with positive slope at all pressures.Reason : Even at low pressures, repulsive forces dominate hydrogen gas.

Assertion : First ionization energy for nitrogen is lower than oxygen.Reason : Across a period effective nuclear charge decreases.

Assertion : ${\text{B}}_2$ molecule is diamagnetic.Reason : The highest occupied molecular orbital is of $\sigma$ type.

Assertion : Rate of hydrolysis of methyl chloride to methanol is higher in $\text{DMF}$ than in water.Reason : Hydrolysis of methyl chloride follows second order kinetics.

Assertion : Galvanised iron does not rust.Reason : Zinc has a more negative electrode potential than iron.

Assertion : Extraction of iron metal from iron oxide ore is carried out by heating with coke.Reason : The reaction ${\text{Fe}}_2{\text{O}}_{3(s)}\to {\text{Fe}}_{(s)}+3/2{\text{O}}_{2(g)}$ is a spontaneous process.

Assertion : Rates of nitration of benzene and hexadeuterobenzene are different.Reason : $\text{C}-\text{H}$ bond is stronger than $\text{C}-\text{D}$ bond.

Assertion : $t$ -Butyl methyl ether is not prepared by the reaction of $t$ -butyl bromide with sodium methoxide.Reason : Sodium methoxide is a strong nucleophile.

Assertion : Maltose is a reducing sugar which gives two moles of $\text{D}$ -glucose on hydrolysis.Reason : Maltose has a $1,4$ -$\beta$ -glycosidic linkage.

118. Assertion: $p{\text{-O}}_2\text{N}-{\text{C}}_6{\text{H}}_4{\text{COCH}}_3$ is prepared by Friedel Crafts acylation of nitrobenzene.
Reason: Nitrobenzene easily undergoes electrophilic substitution reaction.

Assertion : Alkyl isocyanides in acidified water give alkyl formamides.Reason : In isocyanides, carbon first acts as a nucleophile and then as an electrophile.

Assertion : Cyclopentadienyl anion is much more stable than allyl anion.Reason : Cyclopentadienyl anion is aromatic in character.

Based on cellular mechanisms there are two major types of regeneration found in the animals. Which one of the following is the correct example of the type mentioned?

Which one of the following four secretions is correctly matched with its source, target and nature of action?

Which one of the following four glands is correctly matched with the accompanying description?

Given below is a pedigree chart showing the inheritance of a certain sex-linked trait in humans.

The trait traced in the above pedigree chart is:

A cross section at the midpoint of the middle piece of a human sperm will show:

Which one of the following is a correct statement?

An insect bite may result in inflammation of that spot. This is triggered by the alarm chemicals such as:

Which one of the following pairs of geographical areas show maximum biodiversity in our country?

Genetic diversity in agricultural crops is threatened by:

One of the ex-situ conservation methods for endangered species is:

Formation of non-functional methaemoglobin causes blue-baby syndrome. This is due to:

Two of the body parts which do not appear in MRI may be:

A young drug addict used to show symptoms of depressed brain activity, feeling of calmness, relaxation and drowsiness. Possibly he was taking:

Antigen binding site in an antibody is found between:

Which one of the following events is correctly matched with the time period in a normal menstrual cycle?

A tumor inducing plasmid widely used in the production of transgenic plants is that of: