NEET 2018 — Code AA

 H for the formation of XY is – 200 kJ mol – 1 . The bond dissociation energy of X 2 will be

The fundamental frequency in an open organ pipe is equal to the third harmonic of a closed organ pipe. If the length of the closed organ pipe is 20 cm, the length of the open organ pipe is

At what temperature will the rms speed of oxygen molecules become just sufficient for escaping from th e Earth’s atmosphere ? (Given : Mass of oxygen molecule (m) = 2·76  10 – 26 kg Boltzmann’s constant k B = 1·38  10 – 23 J K – 1 )

The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is

A carbon resistor of (47  4·7) k  is to be marked with rings of different colours for its identification. The colour code sequence will be

A set of ‘n’ equal resistors, of value ‘R’ each, are connected in series to a battery of emf ‘E’ and internal resistance ‘R’. The current drawn is I. Now, the ‘n’ resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I. The value of ‘n’ is

The volume (V) of a monatomic gas varies with its temperature (T), as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a change from state A to state B, is

Unpolarised light is incident from air on a plane surface of a material of refractive index ‘  ’. At a particular angle of incidence ‘i’, it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation ?

In Young’s double slit experiment the separation d between the slits is 2 mm, the wavelength  of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0·20  . To increase the fringe angular width to 0·21  (with same  and D) the separation between the slits needs to be changed to

An astronomical refracting telescope will have large angular magnification and high angular resolution, when it has an objective lens of

The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom, is

An electron of mass m with an initial velocity  V = V 0 ^ i (V 0 > 0) enters an electric field  E = – E 0 ^ i (E 0 = constant > 0) at t = 0. If  0 is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is

For a radioactive material, half-life is 10 minutes. If initially there are 600 number of nuclei, the time taken (in minutes) for the disintegration of 450 nuclei is

When the light of frequency 2 v 0 (where v 0 is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is v 1 . When the frequency of the incident radiation is increased to 5 v 0 , the maximum velocity of electrons emitted from the same plate is v 2 . The ratio of v 1 to v 2 is

In the circuit shown in the figure, the input voltage V i is 20 V, V BE = 0 and V CE = 0. The values of I B , I C and  are given by

In a p-n junction diode, change in temperature due to heating

In the combination of the following gates the output Y can be written in terms of inputs A and B as

An em wave is propagating in a medium with a velocity  V = V ^ i . The instantaneous oscillating electric field of this em wave is along +y axis. Then the direction of oscillating magnetic field of the em wave will be along

The refractive index of the material of a prism is 2 and the angle of the prism is 30  . One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface) if its angle of incidence on the prism is

An object is placed at a distance of 40 cm from a concave mirror of focal length 15 cm. If the object is displaced through a distance of 20 cm towards the mirror, the displacement of the image will be

The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance

An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is

The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is

A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperature of 27  C two successive resonances are produced at 20 cm and 73 cm of column length. If the frequency of the tuning fork is 320 Hz, the velocity of sound in air at 27  C is

A pendulum is hung from the roof of a sufficiently high building and is moving freely to and fro like a simple harmonic oscillator. The acceleration of the bob of the pendulum is 20 m/s 2 at a distance of 5 m from the mean position. The time period of oscillation is

A metallic rod of mass per unit length 0·5 kg m – 1 is lying horizontally on a smooth inclined plane which makes an angle of 30  with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction 0·25 T is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is

A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from

An inductor 20 mH, a capacitor 100  F and a resistor 50  are connected in series across a source of emf, V = 10 sin 314 t. The power loss in the circuit is

Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is

A body initially at rest and sliding along a frictionless track from a height h (as shown in the figure) just completes a vertical circle of diameter AB = D. The height h is equal to

Three objects, A : (a solid sphere), B : (a thin circular disk) and C : (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed  about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation

A moving block having mass m, collides with another stationary block having mass 4m. The lighter block comes to rest after collision. When the initial velocity of the lighter block is v, then the value of coefficient of restitution (e) will be

Which one of the following statements is incorrect ?

A toy car with charge q moves on a frictionless horizontal plane surface under the influence of a uniform electric field  E . Due to the force q , E  its velocity increases from 0 to 6 m/s in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and the average speed of the toy car between 0 to 3 seconds are respectively

A block of mass m is placed on a smooth inclined wedge ABC of inclination  as shown in the figure . The wedge is given an acceleration ‘a’ towards the right. The relation between a and  for the block to remain stationary on the wedge is

The moment of the force,  F = 4 ^ i + 5 ^ j – 6 ^ k at (2, 0, – 3), about the point (2, – 2, – 2), is given by

A student measured the diameter of a small steel ball using a screw gauge of least count 0·001 cm. The main scale reading is 5 mm and zero of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of – 0·004 cm, the correct diameter of the ball is

A solid sphere is rotating freely about its symmetry axis in free space. The radius of the sphere is increased keeping its mass same. Which of the following physical quantities would remain constant for the sphere ?

The kinetic energies of a planet in an elliptical orbit about the Sun, at positions A, B and C are K A , K B and K C , respectively. AC is the major axis and SB is perpendicular to AC at the position of the Sun S as shown in the figure. Then

If the mass of the Sun were ten times smaller and the universal gravitational constant were ten times larger in magnitude, which of the following is not correct ?

A solid sphere is in rolling motion. In rolling motion a body possesses translational kinetic energy (K t ) as well as rotational kinetic energy (K r ) simultaneously. The ratio K t : (K t + K r ) for the sphere is

A small sphere of radius ‘r’ falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to

The power radiated by a black body is P and it radiates maximum energy at wavelength,  0 . If the temperature of the black body is now changed so that it radiates maximum energy at wavelength 4 3  0 , the power radiated by it becomes nP. The value of n is

Two wires are made of the same material and have the same volume. The first wire has cross-sectional area A and the second wire has cross-sectional area 3A. If the length of the first wire is increased by  l on applying a force F, how much force is needed to stretch the second wire by the same amount ?

A sample of 0·1 g of water at 100  C and normal pressure (1·013  10 5 Nm – 2 ) requires 54 cal of heat energy to convert to steam at 100  C. If the volume of the steam produced is 167·1 cc, the change in internal energy of the sample, is

The correct order of N-compounds in its decreasing order of oxidation states is

Which one of the following elements is unable to form – 3 6 MF ion ?

Considering Ellingham diagram, which of the following metals can be used to reduce alumina ?

The correct order of atomic radii in group 13 elements is

Which of the following statements is not true for halogens ?

In the structure of ClF 3 , the number of lone pairs of electrons on central atom ‘Cl’ is

Which of the following compounds can form a zwitterion ?

Regarding cross-linked or network polymers, which of the following statements is incorrect ?

Nitration of aniline in strong acidic medium also gives m-nitroaniline because

The difference between amylose and amylopectin is

A mixture of 2·3 g formic acid and 4·5 g oxalic acid is treated with conc. H 2 SO 4 . The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be

Which of the following oxides is most acidic in nature ?

Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity ?

The compound A on treatment with Na gives B, and with PCl 5 gives C. B and C react together to give diethyl ether. A, B and C are in the order

The compound C 7 H 8 undergoes the following reactions : The product ‘C’ is

Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is

Which of the following molecules represents the order of hybridisation sp 2 , sp 2 , sp, sp from left to right atoms ?

Which of the following is correct with respect to – I effect of the substituents ? (R = alkyl)

In the reaction the electrophile involved is

Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their

Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code : Column I Column II a. Co 3+ i. 8 B.M. b. Cr 3+ ii. 35 B.M. c. Fe 3+ iii. 3 B.M. d. Ni 2+ iv. 24 B.M. v. 15 B.M. a b c d

Which one of the following ions exhibits d-d transition and paramagnetism as well ?

Iron carbonyl, Fe(CO) 5 is

The type of isomerism shown by the complex [CoCl 2 (en) 2 ] is

The geometry and magnetic behaviour of the complex [Ni(CO) 4 ] are

Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations : a. 60 mL 10 M HCl + 40 mL 10 M NaOH b. 55 mL 10 M HCl + 45 mL 10 M NaOH c. 75 mL 5 M HCl + 25 mL 5 M NaOH d. 100 mL 10 M HCl + 100 mL 10 M NaOH pH of which one of them will be equal to 1 ?

On which of the following properties does the coagulating power of an ion depend ?

Given van der Waals constant for NH 3 , H 2 , O 2 and CO 2 are respectively 4·17, 0·244, 1·36 and 3·59, which one of the following gases is most easily liquefied ?

The solubility of BaSO 4 in water is 2·42  10 – 3 gL – 1 at 298 K. The value of its solubility product (K sp ) will be (Given molar mass of BaSO 4 = 233 g mol – 1 )

In which case is the number of molecules of water maximum ?

The correct difference between first- and second-order reactions is that

Among CaH 2 , BeH 2 , BaH 2 , the order of ionic character is

Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below : Then the species undergoing disproportionation is

For the redox reaction Mn – 4 O + C 2 – 2 4 O + H +   Mn 2+ + CO 2 + H 2 O the correct coefficients of the reactants for the balanced equation are Mn – 4 O – 2 4 2 O C H +

Which one of the following conditions will favour maximum formation of the product in the reaction, A 2 (g) + B 2 (g)  X 2 (g)  r H = – X kJ ?

When initial concentration of the reactant is doubled, the half-life period of a zero order reaction

The correction factor ‘a’ to the ideal gas equation corresponds to

Consider the following species : CN + , CN – , NO and CN Which one of these will have the highest bond order ?

Magnesium reacts with an element (X) to form an ionic compound. If the ground state electronic configuration of (X) is 1s 2 2s 2 2p 3 , the simplest formula for this compound is

Iron exhibits bcc structure at room temperature. Above 900  C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900  C (assuming molar mass and atomic radii of iron remains constant with temperature) is

Which one is a wrong statement ?

Oxygen is not produced during photosynthesis by

Double fertilization is

Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other ?

Pollen grains can be stored for several years in liquid nitrogen having a temperature of

Which of the following elements is responsible for maintaining turgor in cells ?

What is the role of NAD + in cellular respiration ?

In which of the following forms is iron absorbed by plants ?

Which of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes ?

Use of bioresources by multinational companies and organisations without authorisation from the concerned country and its people is called

In India, the organisation responsible for assessing the safety of introducing genetically modified organisms for public use is

The correct order of steps in Polymerase Chain Reaction (PCR) is

Select the correct match :

A ‘new’ variety of rice was patented by a foreign company, though such varieties have been present in India for a long time. This is related to

Which of the following pairs is wrongly matched ?

Select the correct statement :

The experimental proof for semiconservative replication of DNA was first shown in a

Which of the following flowers only once in its life-time ?

Offsets are produced by

Select the correct match :

Which of the following has proved helpful in preserving pollen as fossils ?

Natality refers to

World Ozone Day is celebrated on

Which of the following is a secondary pollutant ?

Niche is

What type of ecological pyramid would be obtained with the following data ? Secondary consumer : 120 g Primary consumer : 60 g Primary producer : 10 g

In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and release of molecular oxygen ?

The two functional groups characteristic of sugars are

Which among the following is not a prokaryote ?

The Golgi complex participates in

Which of the following is not a product of light reaction of photosynthesis ?

Which of the following is true for nucleolus ?

Stomatal movement is not affected by

The stage during which separation of the paired homologous chromosomes begins is

Stomata in grass leaf are

Secondary xylem and phloem in dicot stem are produced by

Pneumatophores occur in

Casparian strips occur in

Plants having little or no secondary growth are

Sweet potato is a modified

Which of the following statements is correct ?

Select the wrong statement :

After karyogamy followed by meiosis, spores are produced exogenously in

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Herbarium i. It is a place having a collection of preserved plants and animals. b. Key ii. A list that enumerates methodically all the species found in an area with brief description aiding identification. c. Museum iii. Is a place where dried and pressed plant specimens mounted on sheets are kept. d. Catalogue iv. A booklet containing a list of characters and their alternates which are helpful in identification of various taxa. a b c d

Winged pollen grains are present in

Which one is wrongly matched ?

Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively ?

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Tricuspid valve i. Between left atrium and left ventricle b. Bicuspid valve ii. Between right ventricle and pulmonary artery c. Semilunar valve iii. Between right atrium and right ventricle a b c

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Tidal volume i. 2500 – 3000 mL b. Inspiratory Reserve ii. 1100 – 1200 mL volume c. Expiratory Reserve iii. 500 – 550 mL volume d. Residual volume iv. 1000 – 1100 mL a b c d

The transparent lens in the human eye is held in its place by

Which of the following is an amino acid derived hormone ?

Which of the following hormones can play a significant role in osteoporosis ?

Which of the following structures or regions is incorrectly paired with its function ?

The amnion of mammalian embryo is derived from

Hormones secreted by the placenta to maintain pregnancy are

The difference between spermiogenesis and spermiation is

The contraceptive ‘SAHELI’

Ciliates differ from all other protozoans in

Identify the vertebrate group of animals characterized by crop and gizzard in its digestive system.

Which of the following features is used to identify a male cockroach from a female cockroach ?

Which one of these animals is not a homeotherm ?

Which of the following animals does not undergo metamorphosis ?

Which of the following organisms are known as chief producers in the oceans ?

Which one of the following population interactions is widely used in medical science for the production of antibiotics ?

All of the following are included in ‘Ex -situ conservation’ except

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Eutrophication i. UV-B radiation b. Sanitary landfill ii. Deforestation c. Snow blindness iii. Nutrient enrichment d. Jhum cultivation iv. Waste disposal a b c d

In a growing population of a country,

Which part of poppy plant is used to obtain the drug ‘‘Smack’’ ?

All of the following are part of an operon except

A woman has an X-linked condition on one of her X chromosomes. This chromosome can be inherited by

According to Hugo de Vries, the mechanism of evolution is

AGGTATCGCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA ?

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Proliferative Phase i. Breakdown of endometrial lining b. Secretory Phase ii. Follicular Phase c. Menstruation iii. Luteal Phase a b c

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Glycosuria i. Accumulation of uric acid in joints b. Gout ii. Mass of crystallised salts within the kidney c. Renal calculi iii. Inflammation in glomeruli d. Glomerular iv. Presence of glucose in nephritis urine a b c d

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II (Function) (Part of Excretory System) a. Ultrafiltration i. Henle’s loop b. Concentration ii. Ureter of urine c. Transport of iii. Urinary bladder urine d. Storage of urine iv. Malpighian corpuscle v. Proximal convoluted tubule a b c d

Which of the following gastric cells indirectly help in erythropoiesis ?

Match the items given in Column I with those in Column II and select the correct option given below : Column I Column II a. Fibrinogen i. Osmotic balance b. Globulin ii. Blood clotting c. Albumin iii. Defence mechanism a b c

Which of the following is an occupational respiratory disorder ?

Calcium is important in skeletal muscle contraction because it

Nissl bodies are mainly composed of

Which of these statements is incorrect ?

Select the incorrect match :

Which of the following terms describe human dentition ?

Which of the following events does not occur in rough endoplasmic reticulum ?

Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as

In which disease does mosquito transmitted pathogen cause chronic inflammation of lymphatic vessels ?

Which of the following is not an autoimmune disease ?

Among the following sets of examples for divergent evolution, select the incorrect option :

Conversion of milk to curd improves its nutritional value by increasing the amount of

The similarity of bone structure in the forelimbs of many vertebrates is an example of

Which of the following characteristics represent ‘Inheritance of blood groups’ in humans ? a. Dominance b. Co-dominance c. Multiple allele d. Incomplete dominance e. Polygenic inheritance