NEET Practice Paper 2021

Two charged spherical conductors of radius R₁ and R₂ are connected by a wire. Then the ratio of surface charge densities of the spheres  σ1/σ2 is

The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is d/2, then the viscous force acting on the ball will be

An infinitely long straight conductor carries a current of 5 A as shown. An electron is moving with a speed of 10⁵ m/s parallel to the conductor. The perpendicular distance between the electron and the conductor is 20 cm at an instant. Calculate the magnitude of the force experienced by the electron at that instant.

A dipole is placed in an electric field as shown. In which direction will it move?

A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since

A screw gauge gives the following readings when used to measure the diameter of a wire

Main scale reading : 0 mm.

Circular scale reading : 52 divisions.

Given that 1 mm on main scale corresponds to 100 divisions on the circular scale. The diameter of the wire from the above data is

A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding energy per nucleon of unfragmented nuclei is 7.6 MeV while that of fragments is 8.5 MeV. The total gain in the Binding Energy in the process is

A small block slides down on a smooth inclined plane, starting from rest at time t = 0.

Let S_n be the distance travelled by the block in the interval t = n – 1 to t = n.

Then, the ratio S_n / S_n+1 is

Find the value of the angle of emergence from the prism. Refractive index of the glass is √3

A spring is stretched by 5 cm by a force 10 N. The  time period of the oscillations when a mass of 2 kg is suspended by it is

A convex lens ‘A’ of focal length 20 cm and a concave lens ‘B’ of focal length 5 cm are kept along the same axis with a distance ‘d’ between them. If a parallel beam of light falling on ‘A’ leaves ‘B’ as a parallel beam, then the distance ‘d’ in cm will be

Column-I gives certain physical terms associated with flow of current through a metallic conductor.
Column-II gives some mathematical relations involving electrical quantities.

Match Column-I and Column-II with appropriate relations

The electron concentration in an n-type semiconductor is the same as hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.

A radioactive nucleus  undergoes spontaneous decay in the sequence

where Z is the atomic number of element X.

The possible decay particles in the sequence are

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine?
(g = 10 m/s²)

The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of 3.3 × 10^-3 watt will be

(h = 6.6 × 10–34 J s)

For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

The effective resistance of a parallel connection that consists of four wires of equal length, equal area of cross-section and same material is 0.25 ohm. What will be the effective resistance if they are connected in series?

In a potentiometer circuit a cell of EMF 1.5 V gives balance point at 36 cm length of wire. If another cell of EMF 2.5 V repaces the first cell, then at what length of the wire, the balance point occurs?

Polar molecules are the molecules

A parallel plate capacitor has a uniform electric field in the space between the plates. If the distance between the plates is ‘d’ and the area of each plate is ‘A’, the energy stored in the capacitor is

(ε₀ = permittivity of free space)

The equivalent capacitance of the combination shown in the figure is

Consider the following statements (A) and (B) and  identify the correct answer.
(A) A zener diode is connected in reverse bias, when used as a voltage regulator.
(B) The potential barrier of p-n junction lies between 0.1 V to 0.3 V.

A particle is released from height S from the surface of the Earth. At a certain height its kinetic energy is three times its potential energy. The height from the surface of earth and the speed of the particle at that instant are respectively.

If E and G respectively denote energy and gravitational constant, then E/G has the dimensions of

Match Column – I and Column – II and choose the correct match from the given choices.

A body is executing simple harmonic motion with frequency ‘n’, the frequency of its potential energy is

A cup of coffee cools from 90°C to 80°C in t minutes,when the room temperature is 20°C. The time taken by a similar cup of coffee to cool from 80°C to 60°C at a room temperature same at 20°C is

A capacitor of capacitance ‘C’, is connected across an ac source of voltage V, given by
V = V₀sinωt
The displacement current between the plates of the capacitor, would then be given by

The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be

An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance ‘R’ are connected in series to an ac source of potential difference ‘V’ volts as shown in figure. Potential difference across L, C and R is 40 V, 10 V and 40 V, respectively. The amplitude of current flowing through LCR series circuit is 10 2 A . The impedance of the circuit is

A thick current carrying cable of radius ‘R’ carries current ‘I’ uniformly distributed across its cross-section. The variation of magnetic field B(r) due to the cable with the distance ‘r’ from the axis of the cable is represented by

An electromagnetic wave of wavelength ‘λ’ is incident on a photosensitive surface of negligible work  function. If ‘m’ mass is of photoelectron emitted from the surface has de-Broglie wavelength ‘λ_d‘ , then

The escape velocity from the Earth’s surface is v. The escape velocity from the surface of another planet having a radius, four times that of Earth and same mass density is

If force [F], acceleration [A] and time [T] are chosen as the fundamental physical quantities. Find the dimensions of energy

Two conducting circular loops of radii R₁ and R₂ are placed in the same plane with their centres coinciding. If R₁ > R ₂the mutual inductance M between them will be directly proportional to

A point object is placed at a distance of 60 cm froma convex lens of focal length 30 cm. If a plane mirror were put perpendicular to the principal axis of the lens and at a distance of 40 cm from it, the final image would be formed at a distance of

Three resistors having resistances r₁, r₂ and r₃ are connected as shown in the given circuit. The ratio  i3/i1 of currents in terms of resistances used in the circuit is

For the given circuit, the input digital signals are applied at the terminals A, B and C. What would be the output at the terminal y?

A series LCR circuit containing 5.0 H inductor, 80 µF capacitor and 40 Ω resistor is connected to 230V variable frequency ac source. The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be

A car starts from rest and accelerates at 5 m/s². At t = 4 s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t = 6 s? (Take g = 10 m/s²)

A particle of mass ‘m’ is projected with a velocity v = kV_e (k < 1) from the surface of the earth. (V_e = escape velocity)

The maximum height above the surface reached by the particle is

A particle moving in a circle of radius R with a uniform speed takes a time T to complete one revolution. If this particle were projected with the same speed at an angle θ to the horizontal, the maximum height attained by it equals 4R. The angle of projection, θ , is then given by

In the product

A ball of mass 0.15 kg is dropped from a height 10 m, strikes the ground and rebounds to the same height.The magnitude of impulse imparted to the ball is (g = 10 m/s²) nearly

A uniform conducting wire of length 12a and resistance ‘R’ is wound up as a current carrying coil in the shape of,

(i) an equilateral triangle of side ‘a’.
(ii) a square of side ‘a’.

The magnetic dipole moments of the coil in each case respectively are

Twenty seven drops of same size are charged at 200 V each. They combine to form a bigger drop.Calculate the potential of the bigger drop

A uniform rod of length 200 cm and mass 500 g is balanced on a wedge placed at 40 cm mark. A mass of 2 kg is suspended from the rod at 20 cm and another unknown mass ‘m’ is suspended from the rod at 160 cm mark as shown in the figure. Find the value of ‘m’ such that the rod is in equilibrium.
(g = 10 m/s²)

From a circular ring of mass ‘M’ and radius ‘R’ an arc corresponding to a 90° sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the centre of the ring and perpendicular to the plane of the ring is ‘K’ times ‘MR²’.

Then the value of ‘K’ is

A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

Dihedral angle of least stable conformer of ethane is :

Noble gases are named because of their inertness towards reactivity. Identify an incorrect statement about them.

The major product of the following chemical reaction is :

A particular station of All India Radio, New Delhi broadcasts on a frequency of 1,368 kHz (kilohertz).
The wavelength of the electromagnetic radiation emitted by the transmitter is :

[speed of light c = 3.0 × 10⁸ ms^-1]

The incorrect statement among the following is :

Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are :

Identify the compound that will react with Hinsberg’s reagent to give a solid which dissolves in alkali

Which of the following reactions is the metal displacement reaction?

Choose the right option.

Given below are two statements :

Statement I :

Aspirin and Paracetamol belong to the class of narcotic analgesics.

Statement II :

Morphine and Heroin are non-narcotic analgesics. In the light of the above statements, choose the correct answer from the options given below.

What is the IUPAC name of the organic compound formed in the following chemical reaction?

Statement I :

Acid strength increases in the ordergiven as HF << HCl << HBr << HI. Statement II :

As the size of the elements F, Cl, Br,I increases down the group, the bond strength of HF,HCl, HBr and HI decreases and so the acid strength increases.I n the light of the above statements, choose the correct answer from the options given below.

Which one among the following is the correct option for right relationship between C_P and C_V for one mole of ideal gas?

(1) C_P+C_V=R
(2) C_P−C_V=R
(3) C_P=RC_V
(4) C_V=RC_P

Match List-I with List-II.

Choose the correct answer from the options given below.

The following solutions were prepared by dissolving 10 g of glucose (C₆H₁₂O₆) in 250 ml of water (P₁),10 g of urea (CH₄N₂₀) in 250 ml of water (P₂) and 10 g of sucrose (C₁₂H₂₂O₁₁) in 250 ml of water (P₃).
The right option for the decreasing order of osmotic pressure of these solutions is :

Which one of the following methods can be used to obtain highly pure metal which is liquid at room temperature?

Tritium, a radioactive isotope of hydrogen, emits which of the following particles?

The correct option for the number of body centred unit cells in all 14 types of Bravais lattice unit cells is :

The major product formed in dehydrohalogenation reaction of 2-Bromo pentane is Pent-2-ene. This product formation is based on?

The maximum temperature that can be achieved in blast furnace is :

The molar conductance of NaCl, HCl and CH₃COONa at infinite dilution are 126.45, 426.16 and 91.0 S cm2 mol–1 respectively. The molar conductance of CH₃COOH at infinite dilution is.
Choose the right option for your answer

Ethylene diaminetetraacetate (EDTA) ion is :

The structures of beryllium chloride in solid state and vapour phase, are :

The correct structure of 2, 6-Dimethyl-dec-4-ene is

The right option for the statement “Tyndall effect is exhibited by”, is :

Which one of the following polymers is prepared by addition polymerisation?

The RBC deficiency is deficiency disease of :

The correct sequence of bond enthalpy of ‘C—X’ bond is :

An organic compound contains 78% (by wt.) carbon and remaining percentage of hydrogen. The right option for the empirical formula of this compound
is : [Atomic wt. of C is 12, H is

Among the following alkaline earth metal halides, one which is covalent and soluble in organic solvents is :

BF₃ is planar and electron deficient compound. Hybridization and number of electrons around the central atom, respectively are :

The pK_b of dimethylamine and pKa_a of acetic acid are 3.27 and 4.77 respectively at T (K). The correct option for the pH of dimethylammonium acetate
solution is :

Choose the correct option for graphical representation of Boyle’s law, which shows a graph of pressure vs volume of a gas at different temperatures :

For a reaction A -> B, enthalpy of reaction is –4.2 kJ mol–1 and enthalpy of activation is9.6 kJ mol^-1. The correct potential energy profile for
the reaction is shown in option

The compound which shows metamerism is :

Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of :

Match List-I with List-II.

Choose the correct answer from the options given below.

The reagent ‘R’ in the given sequence of chemical reaction is:

From the following pairs of ions which one is not an iso-electronic pair?

The slope of Arrhenius plot ( ln k v/s 1/T) of first order reaction is –5 × 10³K. The value of E_a of the reaction is.

Choose the correct option for your answer.

[Given R = 8.314 JK^-1mol^-1]

For irreversible expansion of an ideal gas under isothermal condition, the correct option is:

In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it?

The intermediate compound ‘X’ in the following chemical reaction

The correct option for the value of vapour pressure of a solution at 45°C with benzene to octane in molar ratio 3 : 2 is :

[At 45°C vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg. Assume Ideal gas]

The molar conductivity of 0.007 M acetic acid is 20 S cm² mo^-1. What is the dissociation constant of acetic acid?

Choose the correct option.

Consider the below reaction and identify the missing reagent/chemical.

Choose the correct answer from the options given above

The product formed in the following chemical reaction is:

Which of the following molecules is non-polar in nature?

Match List-I with List-II.

Choose the correct answer from the options given below.

Choose the correct option for the total pressure (in atm.) in a mixture of 4 g O₂ and 2 g H₂ confined in a total volume of one litre at 0°C is :

[Given R = 0.082 L atm mol^-1K^-1, T = 273 K]

Which of the following plants is monoecious?

A typical angiosperm embryo sac at maturity is:

Gemmae are present in

When the centromere is situated in the middle of two equal arms of chromosomes, the chromosome is referred as :

Which of the following stages of meiosis involves division of centromere?

The first stable product of CO₂ fixation in Sorghum is

The factor that leads to Founder effect in a population is :

Which of the following is an incorrect statement?

Amensalism can be represented as:

The amount of nutrients, such as carbon, nitrogen,phosphorus and calcium present in the soil at any given time, is referred as :

Which of the following algae contains mannitol as reserve food material?

Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival?

Genera like Selaginella and Salvinia produce two kinds of spores. Such plants are known as:

The site of perception of light in plants during photoperiodism is

Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called

Match List-I with List-II.

Choose the correct answer from the options given below

Match List-I with List-II

Choose the correct answer from the options given below.

DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as

The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which, during pollination, brings genetically different types of pollen grains to stigma, is :

Which of the following algae produce Carrageen?

Which of the following statements is not correct?

In the equation GPP – R = NPP R represents :

Diadelphous stamens are found in

When gene targetting involving gene amplification isattempted in an individual’s tissue to treat disease,it is known as :

Match List-I with List-II.

Choose the correct answer from the options given below.

The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called :

Which of the following is a correct sequence ofsteps in a PCR (Polymerase Chain Reaction)?

Mutations in plant cells can be induced by:

Match List-I with List-I

Choose the correct answer from the options given below.

During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out :

Complete the flow chart on central dogma

Which of the following is not an application of PCR(Polymerase Chain Reaction)?

The plant hormone used to destroy weeds in a field

Match List-I with List-II

Select the correct answer from the options given below.

Which of the following are not secondary metabolites in plants?

Which of the following statements is incorrect?

Match Column-I with Column-II

Choose the correct answer from options given below.

Match Column-I with Column-II

Select the correct answer from the options given below.

Identify the correct statement.

Which of the following statements is correct ?

Select the correct pair.

DNA fingerprinting involves identifying differences in some specific regions in DNA sequence, called as

In some members of which of the following pairs of families, pollen grains retain their viability for months after release?

Which of the following statements is incorrect?

What is the role of RNA polymerase III in the process of transcription in eukaryotes?

In the exponential growth equation N_t= N₀e ^rt, e represents

Now a days it is possible to detect the mutated gene causing cancer by allowing radioactive probe to hybridise its complimentary DNA in a clone of cells,
followed by its detection using autoradiography because :

Match List-I with List-II.

Choose the correct answer from the options given below.

Match List-I with List-II

Choose the correct answer from the options given below.

Plasmid pBR322 has Pstl restriction enzyme site within gene^R that confers ampicillin resistance.If this enzyme is used for inserting a gene for β-galactoside production and the recombinant plasmid is inserted in an E.coli strain

Identify the incorrect pair

The fruit fly has 8 chromosomes (2n) in each cell.During interphase of Mitosis if the number of chromosomes at G1 phase is 8, what would be the number of chromosomes after S phase

Match List – I with List – II

Choose the correct answer from the options given below.

Match List-I with List-II.

Choose the correct answer from the options given below

If Adenine makes 30% of the DNA molecule, what will be the percentage of Thymine, Guanine and Cytosine in it?

Which of the following RNAs is not required for the synthesis of protein?

Which one of the following is an example of Hormone releasing IUD?

Succus entericus is referred to as:

Chronic auto immune disorder affecting neuron muscular junction leading to fatigue, weakening and paralysis of skeletal muscle is called as:

With regard to insulin choose correct options.

(a) C-peptide is not present in mature insulin.
(b) The insulin produced by rDNA technology has Cpeptide.
(c) The pro-insulin has C-peptide
(d) A-peptide and B-peptide of insulin are interconnected by disulphide bridges.

Choose the correct answer from the options given below

Which one of the following belongs to the family Muscidae?

Which is the “Only enzyme” that has “Capability” to catalyse Initiation, Elongation and Termination in the process of transcription in prokaryotes?

Receptors for sperm binding in mammals are present on :

The centriole undergoes duplication during:

Which one of the following organisms bears hollow and pneumatic long bones?

Erythropoietin hormone which stimulates R.B.C. formation is produced by:

Match the following:

Choose the correct answer from the options given below.

During the process of gene amplification using PCR,if very high temperature is not maintained in thebeginning, then which of the following steps of PCRwill be affected first?

Which of the following statements wrongly represents the nature of smooth muscle?

The organelles that are included in the endomembrane system are

Match List-I with List-II

Choose the correct answer from the options given below.

For effective treatment of the disease, early diagnosis and understanding its pathophysiology is very important. Which of the following molecular diagnostic techniques is very useful for early detection?

Which of the following characteristics is incorrect with respect to cockroach?

Persons with ‘AB’ blood group are called as “Universal recipients”. This is due to :

Dobson units are used to measure thickness of:

Read the following statements

(a) Metagenesis is observed in Helminths.
(b) Echinoderms are triploblastic and coelomate animals.
(c) Round worms have organ-system level of body organization.
(d) Comb plates present in ctenophores help in digestion.
(e) Water vascular system is characteristic of Echinoderms.

Choose the correct answer from the options given below

In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?

Which enzyme is responsible for the conversion of inactive fibrinogens to fibrins?

Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli.

Sphincter of oddi is present at: