NEET 2021
Paper was held on
Sun, Sep 12, 2021 4:30 AM
Biology
1
Which of the following is an incorrect statement?
2
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 :
3
The factor that leads to Founder effect in a population is :
4
The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called :
5
Diadelphous stamens are found in
6
Gemmae are present in
7
A typical angiosperm embryo sac at maturity is :
8
Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival?
9
During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out :
10
DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as
11
Which of the following algae produce Carrageen?
12
Plants follow different pathways in response to environment of phases of life to form different kinds of structures. This ability is called
13
The site of perception of light in plants during photoperiodism is
14
The amount of nutrients, such as carbon, nitrogen, phosphorus and calcium present in the soil at any given time, is referred as :
15
Match List-I with List-II.
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Lenticels | (i) | Phellogen |
| (b) | Cork cambium | (ii) | Suberin deposition |
| (c) | Secondary cortex | (iii) | Exchange of gases |
| (d) | Cork | (iv) | Phelloderm |
Choose the correct answer from the options given below.
16
Which of the following stages of meiosis involves division of centromere?
17
The first stable product of CO2 fixation in Sorghum is
18
Which of the following statements is not correct?
19
Which of the following algae contains mannitol as reverse food material?
20
When gene targetting involving gene amplification is attempted in an individual's tissue to treat disease, it is known as :
21
Match List-I with List-II.
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Cristae | (i) | Primary constriction in chromosome |
| (b) | Thylakoids | (ii) | Disc-shaped sacs in Golgi apparatus |
| (c) | Centromere | (iii) | Infoldings in mitochondria |
| (d) | Cisternae | (iv) | Flattened membranous sacs in stroma of plastids |
Choose the correct answer from the options given below.
22
Match List-I with List-II .
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Protpolast fusion | (i) | Totipotency |
| (b) | Plant tissue culture | (ii) | Pomato |
| (c) | Meristem culture | (iii) | Somaclones |
| (d) | Micropropagation | (iv) | Virus free plants |
Choose the correct answer from the options given below.
23
Complete the flow chart on central dogma.
24
In the equation GPP - R = NPP
R represents :
R represents :
25
When the centromere is situated in the middle of two equal arms of chromosomes, the chromosome is referred as :
26
The plant hormone used to destroy weeds in a field
27
Which of the following are not secondary metabolites in plants?
28
Amensalism can be represented as :
29
Which of the following is not an application of PCR (Polymerase Chain Reaction)?
30
Which of the following is a correct sequence of steps in a PCR (Polymerase Chain Reaction)?
31
Match List-I with List-II.
Select the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Cells with active cell division capacity | (i) | Vascular tissues |
| (b) | Tissue having all cells similar in structure and function | (ii) | Meristematic tissue |
| (c) | Tissue having different types of cells | (iii) | Sclereids |
| (d) | Dead cells with highly thickened walls and narrow lumen | (iv) | Simple tissue |
Select the correct answer from the options given below.
32
Which of the following statements is correct?
33
In the exponential growth equation
Nt = N0ert, e represents
Nt = N0ert, e represents
34
In some members of which of the following pairs of families, pollen grains retain their viability for months after release?
35
Match List-I with List-II.
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | S phase | (i) | Proteins are synthesized |
| (b) | $${G_2}$$ phase | (ii) | Inactive phase |
| (c) | Quiescent stage | (iii) | Interval between mitosis and initiation of DNA replication |
| (d) | $${G_1}$$ phase | (iv) | DNA replication |
Choose the correct answer from the options given below.
36
Match List-I with List-II.
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Protein | (i) | C = C double bonds |
| (b) | Unsaturated fatty acid | (ii) | Phosphodiester bonds |
| (c) | Nucleic acid | (iii) | Glycosidic bonds |
| (d) | Polysaccharide | (iv) | Peptide bonds |
Choose the correct answer from the options given below.
37
Match Column-I with Column-II
Select the correct answer from the options given below.
Select the correct answer from the options given below.
38
What is the role of RNA polymerase III in the process of transcription in eukaryotes?
39
Which of the following statements is incorrect?
40
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:
41
DNA fingerprinting involves identifying differences in some specific regions in DNA sequence, called as
42
Which of the following statements is incorrect?
43
Plasmid pBR322 has Pst I restriction enzyme site within gene ampR that confers ampicillin resistance. If this enzyme is used for inserting a gene for $$\beta$$-galactoside production and the recombinant plasmid is inserted in an E.coli strain
44
Identify the correct statement.
45
Select the correct pair.
46
Match List-I with List-II
Choose the correct answer from the options given below
| List-I | List-II | ||
|---|---|---|---|
| (a) | Aspergillus niger | (i) | Acetic Acid |
| (b) | Acetobacter aceti | (ii) | Lactice Acid |
| (c) | Clostridium butylicum | (iii) | Citric Acid |
| (d) | Lactobacillus | (iv) | Butyric Acid |
Choose the correct answer from the options given below
47
Receptors for sperm binding in mammals are present on :
48
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?
49
Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli.
50
Match the following :
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Physalia | (i) | Pearl oyster |
| (b) | Limulus | (ii) | Portuguese Man of War |
| (c) | Ancylostoma | (iii) | Living fossil |
| (d) | Pinctada | (iv) | Hookworm |
Choose the correct answer from the options given below.
51
Which stage of meiotic prophase shows terminalisation of chiasmata as its distinctive feature?
52
If Adenine makes 30% of the DNA molecule, what will be the percentage of Thymine, Guanine and Cytosine in it?
53
The partial pressures (in mm Hg) of oxygen (O2) and carbon dioxide (CO2) at alveoli (the site of diffusion) are :
54
Read the following statements
(1) Metagenesis is observed in Helminths.
(2) Echinoderms are triploblastic and coelomate animals.
(3) Round worms have organ-system level of body organization.
(4) Comb plates present in ctenophores help in digestion.
(5) Water vascular system is characteristic of Echinoderms.
Choose the correct answer from the options given below.
(1) Metagenesis is observed in Helminths.
(2) Echinoderms are triploblastic and coelomate animals.
(3) Round worms have organ-system level of body organization.
(4) Comb plates present in ctenophores help in digestion.
(5) Water vascular system is characteristic of Echinoderms.
Choose the correct answer from the options given below.
55
In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?
56
Which of the following statements wrongly represents the nature of smooth muscle?
57
Which one of the following belongs to the family Muscidae?
58
During the process of gene amplification using PCR, if very high temperature is not maintained in the beginning, then which of the following steps of PCR will be affected first?
59
Match List-I with List-II.
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Metamerism | (i) | Coelenterata |
| (b) | Canal system | (ii) | Ctenophora |
| (c) | Comb plates | (iii) | Annelida |
| (d) | Cnidoblasts | (iv) | Porifera |
Choose the correct answer from the options given below.
60
Which one of the following is an example of Hormone releasing IUD?
61
The centriole undergoes duplication during :
62
Which of the following characteristics is incorrect with respect to cockroach?
63
Veneral diseases can spread through :
(1) Using sterile needles
(2) Transfusion of blood from infected person
(3) Infector mother to foetus
(4) Kissing
(5) Inheritance
Choose the correct answer from the option given below.
(1) Using sterile needles
(2) Transfusion of blood from infected person
(3) Infector mother to foetus
(4) Kissing
(5) Inheritance
Choose the correct answer from the option given below.
64
Which one of the following organisms bears hollow and pneumatic long bones?
65
Persons with 'AB' blood group are called as "Universal recipients". This is due to :
66
The organelles that are included in the endomembrane system are
67
A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is :
68
Identify the incorrect pair
69
With regard to insulin choose correct options.
(1) C-peptide is not present in mature insulin.
(2) The insulin produced by rDNA technology has C-peptide.
(3) The pro-insulin has C-peptide
(4) A-peptide and B-peptide of insulin are interconnected by disulphide bridges.
Choose the correct answer from the options given below.
(1) C-peptide is not present in mature insulin.
(2) The insulin produced by rDNA technology has C-peptide.
(3) The pro-insulin has C-peptide
(4) A-peptide and B-peptide of insulin are interconnected by disulphide bridges.
Choose the correct answer from the options given below.
70
Chronic auto immune disorder affecting neuro muscular junction leading to fatigue, weakening and paralysis of skeletal muscle is called as :
71
Which of the following RNAs is not required for the synthesis of protein?
72
Erythropoietin hormone which stimulates R.B.C formation is produced by :
73
Which enzyme is responsible for the conversion of inactive fibrinogens to fibrins?
74
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?
75
Which is the "Only enzyme" that has "Capability" to catalyse Initiation, Elongation and Termination in the process of transcription in prokaryotes?
76
Match List-I with List-II.
Choose the correct answer from the option given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Vaults | (i) | Entry of sperm through Cervix is blocked |
| (b) | IUDs | (ii) | Removal of Vas deferens |
| (c) | Vasectomy | (iii) | Phagocytosis of sperms within the Uterus |
| (d) | Tubectomy | (iv) | Removal of fallopian tube |
Choose the correct answer from the option given below.
77
Match List-I with List-II
Choose the correct answer from the options given below
| List-I | List-II | ||
|---|---|---|---|
| (a) | Scapula | (i) | Cartilaginous joints |
| (b) | Cranium | (ii) | Flat bone |
| (c) | Sternum | (iii) | Fibrous joints |
| (d) | Vertebral column | (iv) | Triangular flat bone |
Choose the correct answer from the options given below
78
Following are the statements with reference to 'lipids'.
(1) Lipids having only single bonds are called unsaturated fatty acids
(2) Lecithin is a phospholipid.
(3) Trihydroxy propane is glycerol
(4) Palmitic acid has 20 carbon atoms including carboxyl carbon.
(5) Arachidonic acid has 16 carbon atoms.
Choose the correct answer from the options given below.
(1) Lipids having only single bonds are called unsaturated fatty acids
(2) Lecithin is a phospholipid.
(3) Trihydroxy propane is glycerol
(4) Palmitic acid has 20 carbon atoms including carboxyl carbon.
(5) Arachidonic acid has 16 carbon atoms.
Choose the correct answer from the options given below.
79
Match List-I with List-II
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Allen's Rule | (i) | Kangaroo rat |
| (b) | Physiological adaptation | (ii) | Desert lizard |
| (c) | Behavioural adaptation | (iii) | Marine fish at depth |
| (d) | Biochemical adaptation | (iv) | Polar seal |
Choose the correct answer from the options given below.
80
During muscular contraction which of the following events occur?
(1) 'H' zone disappears
(2) 'A' band widens
(3) 'I' band reduces in width
(4) Myosine hydrolyzes ATP, releasing the ADP and Pi.
(5) Z-lines attached to actins are pulled inwards.
Choose the correct answer from the options given below.
(1) 'H' zone disappears
(2) 'A' band widens
(3) 'I' band reduces in width
(4) Myosine hydrolyzes ATP, releasing the ADP and Pi.
(5) Z-lines attached to actins are pulled inwards.
Choose the correct answer from the options given below.
81
Match List-I with List-II.
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | Adaptive radiation | (i) | Selection of resistant varieties due to excessive use of herbicides and pesticides |
| (b) | Convergent evolution | (ii) | Bones of forelimbs in Man and Whale |
| (c) | Divergent evolution | (iii) | Wings of Butterfly and Bird |
| (d) | Evolution by anthropogenic action | (iv) | Darwin Finches |
Choose the correct answer from the options given below.
82
Assertion (A) : A person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations.
Reason (R) : Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen.
In the light of the above statements, choose the correct answer from the options given below
Reason (R) : Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen.
In the light of the above statements, choose the correct answer from the options given below
83
Which of these is not an important component of initiation of parturition in humans?
84
Which of the following secretes the hormone, relaxin, during the later phase of pregnancy?
85
Match List-I with List-II
Choose the correct answer from the options given below
| List-I | List-II | ||
|---|---|---|---|
| (a) | Filariasis | (i) | Haemophilus influenzae |
| (b) | Amoebiasis | (ii) | Trichophyton |
| (c) | Pneumonia | (iii) | Wuchereria bancrofti |
| (d) | Ringworm | (iv) | Entamoeba histolytica |
Choose the correct answer from the options given below
86
The Adenosine deaminase deficiency results into
87
Which one of the following statements about histones is wrong?
88
Statement I : The codon 'AUG' codes for methionine and phenylalanine.
Statement II : 'AAA' and 'AAG' both codons code for the amino acid lysine.
In the light of the above statements, choose the correct answer from the options given below.
Statement II : 'AAA' and 'AAG' both codons code for the amino acid lysine.
In the light of the above statements, choose the correct answer from the options given below.
89
Identify the types of cell junctions that help to stop the leakage of the substances across a tissue and facilitation of communication with neighbouring cells via rapid transfer of ions and molecules.
90
Following are the statements about prostomium of earthworm.
(1) It serves as a covering for mouth.
(2) It helps to open cracks in the soil into which it can crawl.
(3) It is one of the sensory structures.
(4) It is the first body segment.
Choose the correct answer from the options given below.
(1) It serves as a covering for mouth.
(2) It helps to open cracks in the soil into which it can crawl.
(3) It is one of the sensory structures.
(4) It is the first body segment.
Choose the correct answer from the options given below.
Chemistry
1
The incorrect statement among the following is :
2
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.
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.
3
Statement I : Acid strength increases in the order given 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.
In the light of the above statements, choose the correct answer from the options given below.
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.
In the light of the above statements, choose the correct answer from the options given below.
4
Which one among the following is the correct option for right relationship between CP and CV for one mole of ideal gas?
5
BF3 is planar and electron deficient compound. Hybridization and number of electrons around the central atom, respectively are :
6
The major product of the following chemical reaction is :
7
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.
8
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 $$\times$$ 108 ms$$-$$1]
9
Which of the following reactions is the metal displacement reaction? Choose the right option.
10
The compound which shows metamerism is :
11
Match List - I with List - II :
Choose the correct answer from the options given below.
| List - I | List - II | ||
|---|---|---|---|
| (a) | $$PC{l_5}$$ | (i) | Square pyramidal |
| (b) | $$S{F_6}$$ | (ii) | Trigonal planar |
| (c) | $$Br{F_5}$$ | (iii) | Octahedral |
| (d) | $$B{F_3}$$ | (iv) | Trigonal bipyramidal |
Choose the correct answer from the options given below.
12
Identify the compound that will react with Hinsberg's reagent to give a solid which dissolves in alkali.
13
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of :
14
Ethylene diaminetetraacetate (EDTA) ion is :
15
The major product formed in dehydrohalogenation reaction of 2-Bromo pentane is Pent-2-ene. This product formation is based on?
16
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 1]
17
The pKb of dimethyl amine and pKa of acetic acid are 3.27 and 4.77 respectively at T (K). The correct option for the pH of dimethyl ammonium acetate solution is :
18
The correct structure of 2, 6-dimethyl-dec-4-ene is
19
The following solutions were prepared by dissolving 10 g of glucose (C6H12O6) in 250 ml of water (P1), 10 g of urea (CH4N2O) 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 :
20
The correct sequence of bond enthalpy of 'C-X' bond is :
21
Dihedral angle of least stable conformer of ethane is :
22
Noble gases are named because of their inertness towards reactivity. Identify an incorrect statement about them.
23
What is the IUPAC name of the organic compound formed in the following chemical reaction?
24
For a reaction, A $$\to$$ B, enthalpy of reaction is $$-$$4.2 kJ mol$$-$$1 and enthalpy of activation is 9.6 kJ mol$$-$$1. The correct potential energy profile for the reaction is shown in option.
25
Consider the above reaction and identify the missing reagent/chemical.
26
The correct option for the value of vapour pressure of a solution at 45$$^\circ$$C with benzene to octane in molar ratio 3 : 2 is :
[At 45$$^\circ$$C vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg. Assume Ideal gas]
[At 45$$^\circ$$C vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg. Assume Ideal gas]
27
Match List-I with List-II
Choose the correct answer from the options given below.
Choose the correct answer from the options given below.
28
The intermediate compound 'X' in the following chemical reaction is :
29
The product formed in the following chemical reaction is :
30
The slope of Arrhenius plot $$\left( {\ln \,k\,v/s{1 \over T}} \right)$$ of first order reactino is $$-$$5 $$\times$$ 103K. The value of Ea of the reaction is. Choose the correct option for your answer.
[Given R = 8.314 JK$$-$$1mol$$-$$1]
[Given R = 8.314 JK$$-$$1mol$$-$$1]
31
For irreversible expansion of an ideal gas under isothermal condition, the correct option is :
32
From the following pairs of ions which one is not an iso-electronic pair?
33
The molar conductivity of 0.007 M acetic acid is 20 S cm2 mol$$-$$1. What is the dissociation constant of acetic acid? Choose the correct option.
[$$\Lambda _{{H^ + }}^o$$ = 350 S cm2 mol$$-$$1
$$\Lambda _{C{H_3}CO{O^ - }}^o$$ = 50 S cm2 mol$$-$$1]
[$$\Lambda _{{H^ + }}^o$$ = 350 S cm2 mol$$-$$1
$$\Lambda _{C{H_3}CO{O^ - }}^o$$ = 50 S cm2 mol$$-$$1]
34
Which of the following molecules is non-polar in nature?
35
Match List-I with List-II :
Choose the correct answer from the options given below.
| List-I | List-II | ||
|---|---|---|---|
| (a) | $${[Fe{(CN)_6}]^{3 - }}$$ | (i) | 5.92 BM |
| (b) | $${[Fe{({H_2}O)_6}]^{3 + }}$$ | (ii) | 0 BM |
| (c) | $${[Fe{(CN)_6}]^{4 - }}$$ |
(iii) | 4.90 BM |
| (d) | $${[Fe{({H_2}O)_6}]^{2 + }}$$ |
(iv) | 1.73 BM |
Choose the correct answer from the options given below.
36
In which one of the following arrangements the given sequence is not strictly according to the properties indicted against it?
Physics
1
The E and G respectively denote energy and gravitational constant, then $${E \over G}$$ has the dimensions of :
2
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 40V, 10V and 40V, respectively. The amplitude of current flowing through LCR series circuit is 10$$\sqrt 2 $$ A. The impedance of the circuit is :
3
A body is executing simple harmonic motion with frequency 'n', the frequency of its potential energy is :
4
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 :
5
A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding per nucleon of unfragmented nuclei is 7.6MeV while that of fragments is 8.5MeV. The total gain in the Binding Energy in the process is :
6
A parallel plate capacitor has a uniform electric field $$\overrightarrow E $$ 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 : ($$\varepsilon $$0 = permittivity of free space)
7
The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600nm, when it delivers the power of 3.3 $$\times$$ 10$$-$$3 watt will be : (h = 6.6 $$\times$$ 10$$-$$34 Js)
8
Polar molecules are the molecules :
9
A capacitor of capacitance 'C', is connected across an ac source of voltage V, given by
V = V0sin$$\omega$$t
The displacement current between the plates of the capacitor, would then be given by :
V = V0sin$$\omega$$t
The displacement current between the plates of the capacitor, would then be given by :
10
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 :
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 :
11
Find the value of the angle of emergence from the prism. Refractive index of the glass is $$\sqrt 3 $$
12
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 replaces the first cell, then at what length of the wire, the balance point occurs?
13
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 -
14
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$$\Omega$$. What will be the effective resistance if they are connected in series?
15
Water falls from a height of 60m 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)
16
An infinitely long straight conductor carries a current of 5A 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 20cm at an instant. Calculate the magnitude of the force experienced by the electron at that instant.
17
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) 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.
18
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 -
19
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.
20
A dipole is placed in an electric field as shown. In which direction will it move?
21
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 :
22
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 :
23
An electromagnetic wave of wavelength '$$\lambda$$' is incident on a photosensitive surface of negligible work function. If 'm' mass is of photoelectron emitted from the surface has de-Broglie wavelength $$\lambda$$d, then :
24
A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since :
25
Two charged spherical conductors of radius R1 and R2 are connected by a wire. Then the ratio of surface charge densities of the spheres ($$\sigma$$1 / $$\sigma$$2) is :
26
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?
27
A cup of coffee cools from 90$$^\circ$$C to 80$$^\circ$$C in t minutes, when the room temperature is 20$$^\circ$$C. The time taken by a similar cup of coffee to cool from 80$$^\circ$$C to 60$$^\circ$$C at a room temperature same at 20$$^\circ$$C is :
28
The equivalent capacitance of the combination shown in the figure is :
29
If force [F], acceleration [A] and time [T] are chosen as the fundamental physical quantities. Find the dimensions of energy.
30
A small block slides down on a smooth inclined plane, starting from rest at time t = 0. Let Sn be the distance travelled by the block in the interval t = n $$-$$ 1 to t = n. The the ratio $${{{S_n}} \over {{S_{n + 1}}}}$$ is :
31
The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerin becomes constant after some time. If the density of glycerin is $${d \over 2}$$, then the viscous force acting on the ball will be :
32
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.
| Column - I | Column - II | ||
|---|---|---|---|
| (A) | Drift Velocity | (P) | $${m \over {n{e^2}p}}$$ |
| (B) | Electrical Resistivity | (Q) | $$ne{\upsilon _d}$$ |
| (C) | Relaxation Period | (R) | $${{eE} \over m}\tau $$ |
| (D) | Current Density | (S) | $${E \over J}$$ |
33
Match Column - I and Column - II and choose the correct match from the given choices.
| Column - I | Column - II | ||
|---|---|---|---|
| (A) | Root mean square speed of gas molecules | (P) | $${1 \over 3}nm{\overline v ^2}$$ |
| (B) | Pressure exerted by ideal gas | (Q) | $$\sqrt {{{3RT} \over M}} $$ |
| (C) | Average kinetic energy of a molecule | (R) | $${5 \over 2}RT$$ |
| (D) | Total internal energy of 1 mole of a diatomic gas | (S) | $${3 \over 2}{k_B}T$$ |
34
In the product
$$\overrightarrow F = q\left( {\overrightarrow v \times \overrightarrow B } \right)$$
$$ = q\overrightarrow v \times \left( {B\widehat i + B\widehat j + {B_0}\widehat k} \right)$$
For q = 1 and $$\overrightarrow v = 2\widehat i + 4\widehat j + 6\widehat k$$ and $$\overrightarrow F = 4\widehat i - 20\widehat j + 12\widehat k$$
What will be the complete expression for $$\overrightarrow B $$ ?
$$\overrightarrow F = q\left( {\overrightarrow v \times \overrightarrow B } \right)$$
$$ = q\overrightarrow v \times \left( {B\widehat i + B\widehat j + {B_0}\widehat k} \right)$$
For q = 1 and $$\overrightarrow v = 2\widehat i + 4\widehat j + 6\widehat k$$ and $$\overrightarrow F = 4\widehat i - 20\widehat j + 12\widehat k$$
What will be the complete expression for $$\overrightarrow B $$ ?
35
From a circular ring of mass 'M' and radius 'R' an arc corresponding to a 90$$^\circ$$ sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the center of the ring and perpendicular to the plane of the ring is 'K' times 'MR2'. Then the value of 'K' is :
36
Three resistors having resistances r1, r2 and r3 are connected as shown in the given circuit. The ratio $${{{i_3}} \over {{i_1}}}$$ of currents in terms of resistances used in the circuit is :
37
A ball of mass 0.15 kg is dropped from a height 10m, strikes the ground and rebounds to the same height. The magnitude of impulse imparted to the ball is (g = 10 m/s2) nearly :
38
A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?
39
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 tringle of side 'a'
(ii) A square of side 'a'
The magnetic dipole moments of the coil in each case respectively are :
(i) an equilateral tringle of side 'a'
(ii) A square of side 'a'
The magnetic dipole moments of the coil in each case respectively are :
40
A particle of mass 'm' is projected with a velocity $$\upsilon $$ = kVe = (k < 1) from the surface of the earth. (Ve = escape velocity)
The maximum height above the surface reached by the particle is :
The maximum height above the surface reached by the particle is :
41
A series LCR circuit containing 5.0 H inductor, 80$$\mu$$F capacitor and 40$$\Omega$$ 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 :
42
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 '$$\theta$$' to the horizontal, the maximum height attained by it equals 4R. The angle of projection, $$\theta$$, is then given by :
If this particle were projected with the same speed at an angle '$$\theta$$' to the horizontal, the maximum height attained by it equals 4R. The angle of projection, $$\theta$$, is then given by :
43
Two conducting circular loops of radii R1 and R2 are placed in the same plane with their centres coinciding. If R1 >> R2, the mutual inductance M between them will be directly proportional to :
44
Twenty seven drops of same size are charged at 220V each. They combine to form a bigger drop. Calculate the potential of the bigger drop.
45
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)
46
A point object is placed at a distance of 60 cm from a 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 -
47
A car starts from rest and accelerates at 5m/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)
48
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?
