NEET-UG 2020 Question Paper

A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is π/3. If instead C is removed from the circuit, the phase difference is again π/3 between current and voltage. The power factor of the circuit is :

A wire of length L, area of cross section A is hanging from a fixed support. The length of the wire changes to L₁ when mass M is suspended from its free end. The expression for Young's modulus is :

A long solenoid of 50 cm length having 100 turns carries a current of 2.5 A. The magnetic field at the centre of the solenoid is :
(μ₀ = 4π × 10⁻⁷ T m A⁻¹)

A ray is incident at an angle of incidence i on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is μ, then the angle of incidence is nearly equal to :

In a certain region of space with volume 0.2 m³, the electric potential is found to be 5 V throughout. The magnitude of electric field in this region is :

For which one of the following, Bohr model is not valid?

Light with an average flux of 20 W/cm² falls at a non- reflecting surface at normal incidence having surface area 20 cm². The energy received by the surface during time span of 1 minute is :

An electron is accelerated from rest through a potential difference of V volt. If the de Broglie wavelength of the electron is 1.227 × 10⁻² nm, the potential difference is :

A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth?

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?

A 40 μF capacitor is connected to a 200 V, 50 Hz ac supply. The rms value of the current in the circuit is,nearly:

A ball is thrown vertically downward with a velocity of 20 m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is : (g = 10 m/s²)

A cylinder contains hydrogen gas at pressure of 249 kPa and temperature 27°C.
Its density is : (R = 8.3 J mol⁻¹ K⁻¹)

When a uranium isotope ²³⁵₉₂U is bombarded with a neutron, it generates ⁸⁹₃₆Kr, three neutrons and :

The increase in the width of the depletion region in a p-n junction diode is due to :

The phase difference between displacement an acceleration of a particle in a simple harmonic motion is :

An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 A m⁻¹. The permeability of the material of the rod is :

(μ₀ = 4π × 10⁻⁷ T m A⁻¹)

The quantities of heat required to raise the temperature of two solid copper spheres of radii r₁ and r₂ (r₁ = 1.5 r₂) through 1 K are in the ratio :

Two bodies of mass 4 kg and 6 kg are tied to the ends of a massless string. The string passes over a pulley which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity (g) is :

The mean free path for a gas, with molecular diameter d and number density n can be expressed as :

A short electric dipole has a dipole moment of 16 × 10⁻⁹ C m. The electric potential due to the dipole at a point at a distance of 0.6 m from the centre of the dipole, situated on a line making an angle of 60° with the dipole axis is :
(1 / 4πε₀ = 9 × 10⁹ N m² / C²)

Dimensions of stress are :

The energy required to break one bond in DNA is 10⁻²⁰ J. This value in eV is nearly

In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be

The color code of a resistance is given below

The values of resistance and tolerance, respectively, are

The Brewsters angle i Subscriprt (b) for an interface should be

The capacitance of a parallel plate capacitor with air as medium is 6 μF. With the introduction of a dielectric medium, the capacitance becomes 30 μF. The permittivity of the medium is :

(ε₀ = 8.85 × 10⁻¹² C² N⁻¹ m⁻²)

Find the torque about the origin when a force of 3ĵ N acts on a particle whose position vector is 2k̂ m.

A resistance wire connected in the left gap of a metre bridge balances a 10 Ω resistance in the right gap at a point which divides the bridge wire in the ratio 3 : 2. If the length of the resistance wire is 1.5 m, then the length of 1 Ω of the resistance wire is :

For transistor action, which of the following statements is correct?

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is :

(c = speed of electromagnetic waves)

A charged particle having drift velocity of 7.5 × 10⁻⁴ m s⁻¹ in an electric field of 3 × 10⁻¹⁰ V m⁻¹, has a mobility in m² V⁻¹ s⁻¹ of :

A spherical conductor of radius 10 cm has a charge of 3.2 × 10⁻⁷ C distributed uniformly. What is the magnitude of electric field at a point 15 cm from the centre of the sphere?

(1/4πε₀ = 9 × 10⁹ Nm²/C²)

Taking into account the significant figures, what is th value of 9.99 m − 0.0099 m?

In Young's double slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes:

Two cylinders A and B of equal capacity are connected to each other via a stop cock. A contains an ideal gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stop cock is suddenly opened. The process is:

The energy equivalent of 0.5 g of a substance is:

A capillary tube of radius r is immersed in water andwater rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is:

A screw gauge has least count of 0.01 mm and there are 50 divisions in its circular scale. The pitch of the screw gauge is:

For the logic circuit shown, the truth table is:

The average thermal energy for a mono-atomic gas is :

(k subscript (B) is Boltzmann constant and T, absolute temperature)

The solids which have the negative temperature coefficient of resistance are:

Two particles of mass 5 kg and 10 kg respectively areattached to the two ends of a rigid rod of length 1 m withnegligible mass. The centre of mass of the system fromthe 5 kg particle is nearly at a distance of :

Sucrose on hydrolysis gives:

Elimination reaction of 2-Bromo-pentane to form pent-2-ene is:

(A) β-Elimination reaction

(B) Follows Zaitsev rule

(C) Dehydrohalogenation reaction

(D) Dehydration reaction

The number of Faradays (F) required to produce 20 g of calcium from molten CaCl₂(Atomic mass of Ca = 40 g mol⁻¹) is:

An element has a body centered cubic (bcc) structure with a cell edge of 288 pm. The atomic radius is:

Find out the solubility of Ni(OH)₂ in 0.1 M NaOH. Given that the ionic product of Ni(OH)₂ is 2 × 10⁻¹⁵

For the reaction, 2Cl(g) ⟶ Cl₂(g), the correct option is:

Which of the following is the correct order of increasing field strength of ligands to form coordination compounds?

The calculated spin only magnetic moment of Cr²⁺ ion is

Which of the following set of molecules will have zero dipole moment?

The following metal ion activates many enzymes, participates in the oxidation of glucose to produce ATP and with Na, is responsible for the transmission of nerve signals.

An alkene on ozonolysis gives methanal as one of the product. Its structure is:

Reaction between acetone and methylmagnesium chloride followed by hydrolysis will give:

Which of the following is a natural polymer?

Identify the correct statements from the following:

(A) CO₂(g) is used as refrigerant for ice-cream and frozen food.

(B) The structure of C₆₀ contains twelve six carbon rings and twenty five carbon rings.

(C) ZSM-5, a type of zeolite, is used to convert alcohols into gasoline.

(D) CO is colorless and odourless gas.

The correct option for free expansion of an ideal gas under adiabatic condition is

Which of the following oxoacid of sulphur has –O–O– linkage?

Identify compound X in the following sequence of reactions

The number of protons, neutrons and electrons in ¹⁷⁵₇₁Lu, respectively, are

Identify the incorrect statement.

Which of the following is a cationic detergent?

The freezing point depression constant (Kf) of benzene is 5.12 K kg mol⁻¹. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is (rounded off upto two decimal places)

Identify the incorrect match.

The mixture which shows positive deviation from Raoult's law is

Match the following:

Which of the following is the correct option?

Which one of the following has maximum number of atoms?

Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as

A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following?

Which of the following is not correct about carbon monoxide?

Which of the following is a basic amino acid?

Urea reacts with water to form A which will decompose to form B. B when passed through Cu²⁺(aq), deep blue colour solution C is formed. What is the formula of C from the following?

A mixture of N₂ and Ar gases in a cylinder contains 7 g of N₂ and 8 g of Ar. If the total pressure of the mixture of the gases in the cylinder is 27 bar, the partial pressure of N₂ is:

[Use atomic masses (in g mol⁻¹): N = 14, Ar = 40]

Identify the correct statement from the following:

Hydrolysis of sucrose is given by the following reaction.

Sucrose + H₂O ⇌ Glucose + Fructose

If the equilibrium constant (Kc) is 2 × 10¹³ at 300 K, the value of ΔᵣG° at the same temperature will be:

Identify a molecule which does not exist.

An increase in the concentration of the reactants of a reaction leads to change in

Which of the following alkane cannot be made in good yield by Wurtz reaction?

Which of the following amine will give the carbylamine test?

On electrolysis of dil. sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be

What is the change in oxidation number of carbon in the following reaction?

CH₄(g) + 4Cl₂(g) ⟶ CCl₄(l) + 4HCl(g)

Anisole on cleavage with HI gives

Measuring Zeta potential is useful in determining which property of colloidal solution?

Paper chromatography is an example of

Match the following and identify the correct option.

If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is 6.6 × 10⁹ bp, then the length of the DNA is approximately

Bilaterally symmetrical and acoelomate animals are exemplified by

Match the following columns and select the correct option.

Which is the important site of formation of glycoproteins and glycolipids in eukaryotic cells?

The QRS complex in a standard ECG represents

Match the following columns and select the correct option.

Experimental verification of the chromosomal theory of inheritance was done by

Identify the incorrect statement.

Match the following columns and select the correct option.

Match the organism with its use in biotechnology.

Identify the substances having glycosidic bond and peptide bond, respectively in their structure

Name the enzyme that facilitates opening of DNA helix during transcription.

If the head of cockroach is removed, it may live for few days because

Select the correct events that occur during inspiration.

(i) Contraction of diaphragm

(ii) Contraction of external inter-costal muscles

(iii) Pulmonary volume decreases

(iv) Intra pulmonary pressure increases

By which method was a new breed 'Hisardale' of sheep formed by using Bikaneri ewes and Marino rams?

Which one of the following is the most abundant protein in the animals?

How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits?

The body of the ovule is fused within the funicle at

Which of the following is correct about viroids?

The number of substrate level phosphorylations in one turn of citric acid cycle is

The product(s) of reaction catalyzed by nitrogenase in root nodules of leguminous plants is/are

The rate constant for a first order reaction is 4.606 x 10³ s⁻¹ The time required to reduce 2.0 g of the reactant to 0.2 g is:

Match the following diseases with the causative organism and select the correct option.

From his experiments, S.L. Miller produced amino acids by mixing the following in a closed flask

Which of the following statements is correct?

Match the following with respect to meiosis

Select the correct option from the following

Choose the correct pair from the following

Select the option including all sexually transmitted diseases.

Embryological support for evolution was disapproved by

The roots that originate from the base of the stem are

In gel electrophoresis, separated DNA fragments can be visualized with the help of

Which of the following hormone levels will cause release of ovum (ovulation) from the graafian follicle?

Goblet cells of alimentary canal are modified from

Snow-blindness in Antarctic region is due to

Match the following concerning essential elements and their functions in plants

Select the correct option

Bt cotton variety that was developed by the introduction of toxin gene of Bacillus thuringiensis (Bt) is resistant to

Ray florets have

Montreal protocol was signed in 1987 for control of

Identify the wrong statement with regard to Restriction Enzymes.

The infectious stage of Plasmodium that enters the human body is

Meiotic division of the secondary oocyte is completed

The oxygenation activity of RuBisCO enzyme in photorespiration leads to the formation of

Which of the following statements are true for the phylum-Chordata?

(i) In Urochordata notochord extends from head to tail and it is present throughout their life.

(ii) In Vertebrata notochord is present during the embryonic period only.

(iii) Central nervous system is dorsal and hollow.

(iv) Chordata is divided into 3 subphyla : Hemichordata, Tunicata and Cephalochordata.

Match the following columns and select the correct option.

Which of the following pairs is of unicellular algae?

In light reaction, plastoquinone facilitates the transfer of electrons from

Presence of which of the following conditions in urine are indicative of Diabetes Mellitus?

Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their

Which of the following would help in prevention of diuresis?

Select the correct match

Which of the following is not an attribute of a population?

Which of the following statements about inclusion bodies is incorrect?

The transverse section of a plant shows followinganatomical features:

(i) Large number of scattered vascular bundles surrounded by bundle sheath

(ii) Large conspicuous parenchymatous ground tissue

(iii) Vascular bundles conjoint and closed

(iv) Phloem parenchyma absent

Identify the category of plant and its part :

In relation to Gross primary productivity and Net primary productivity of an ecosystem, which one of the following statements is correct?

In water hyacinth and water lily, pollination takes place by:

Which of the following is put into Anaerobic sludge digester for further sewage treatment?

The process responsible for facilitating loss of water in liquid form from the tip of grass blades at night and in early morning is

Cuboidal epithelium with brush border of microvilli is found in

Select the correct statement.

Which of the following is not an inhibitory substance governing seed dormancy?

According to Robert May, the global species diversity is about

Match the trophic levels with their correct species examples in grassland ecosystem.

Select the correct option

The first phase of translation is

Strobili or cones are found in

Match the following columns and select the correct option.

Some dividing cells exit the cell cycle and enter vegetative inactive stage. This is called quiescent stage (G₀). This process occurs at the end of

Identify the correct statement with reference to human digestive system.

In which of the following techniques, the embryos aretransferred to assist those females who cannot conceive?

The plant parts which consist of two generations - one within the other

(i) Pollen grains inside the anther

(ii) Germinated pollen grain with two male gametes

(iii) Seed inside the fruit

(iv) Embryo sac inside the ovule

Dissolution of the synaptonemal complex occurs during

Match the following columns and select the correct option.

The ovary is half inferior in :

Identify the basic amino acid from the following.

Match the following columns and select the correct option.

Match the following

Choose the correct option from the following

Identify the correct statement with regard to G₁ phase (Gap 1) of interphase.

Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop.

Identify the wrong statement with reference to the gene 'I' that controls ABO blood groups.

Identify the wrong statement with reference to immunity.

The enzyme enterokinase helps in conversion of

The specific palindromic sequence which is recognized by EcoRI is

Which of the following graph represents the variation of resistivity (ρ) with temperature (T) for copper?

HCl was passed through a solution of CaCl₂, MgCl₂ and NaCl. Which of the following compound(s) crystallise(s)?

Which of the following statements is correct?

Match the following columns and select the correct option.

Floridean starch has structure similar to

Which of the following statements is not correct?

Flippers of Penguins and Dolphins are examples of

Which of the following refer to correct example(s) of organisms which have evolved due to changes in environment brought about by anthropogenic action?
(a) Darwin's Finches of Galapagos islands.
(b) Herbicide resistant weeds.
(c) Drug resistant eukaryotes.
(d) Man-created breeds of domesticated animals like dogs.

Identify the wrong statement with reference to transport of oxygen.

The process of growth is maximum during

Which of the following regions of the globe exhibits highest species diversity?

The sequence that controls the copy number of the linked DNA in the vector, is termed

Match the following columns and select the correct option.