 # JEE Main 2021 Answer Key (Out), Papers, Solution – Get Keys Here JEE Main 2021 Answer Key has been released on 28th September 2021 for Paper 2 (A) B.Arch 2 (B) B.Plan. Final Answer key for fourth session has been released. It is released separately for four session in – February, March, April, May sessions. JEE Main is conducted for providing admission into UG engineering/ architecture courses (B.Tech/ B.Arch). These courses are offered by the NITs, IITS & IIITs and other government and non-government engineering institutions. JEE Main exam is organized by the National Testing Agency (NTA). Through this article, candidates can get the JEE Main Answer Keys 2021 and also previous year answer key and question papers with all solutions.

Important Applications Open 2021 :

## JEE Main Answer Keys 2021 – Released (Paper 2) JEE Main 2021 Answer Key & Question Paper has been released on 28th September 2021 for Paper 2 (A) B.Arch & 2 (B) B.Plan. Check here for answer key details. JEE Main 2021 Final Answer Key has been released on 8th September 2021. Click here to view answer key.

JEE Main 2021 Institutional Answer Key has been released for Day 4 (fourth session). Check below for answer keys.

### Institutional Answer Key by Resonance: JEE Main 2021 Answer Key (Memory based) has been released for day 1 (shift 1) for phase 4th. Check below for memory based answer key.

### Memory Based Answer Key (Shift 1)

Q.1 A circle center = (-15, 0) and radius = 15/2. Chord to the circle passes through (-30, 0) & tangent to y2 = 30x. Length of the chord = ?

Q.2 If ln (x+y) = 4xy, find d2y/ dx2 at x = 0.

Q.3 If the sum of distances of point P from (0,0) (0, 1) (1, 0) (1,1) = 18. Locus is at the circle of the diameter. Find d2.

Q.4 Frequency changes from 280 to 400nm. Work function = 2.5eV. Then find the change in the stopping potential.

Q.5 3m long chain on a table. Mass of chain is 3 kg. 2m on the table…if it slips find the kinetic energy.

Q.6 Number of compounds which have a greater freezing point of 0.1M enthanol.

Q.7 How many electrons are present in 4f orbital of Gd2+.

Answer. 7 outermost configuration is 4f*7 5d*1

Q.8 S1: Frenkel defect is shown as interstitial as well as vacancy defect.
S2: In Frenkel defect, solids show colour due to F-center.

Answer. Both S1 & S2 are incorrect

Q.9 Interhalogen compound AB3 has a T-shaped structure, home many lone pairs are present on A?

Q.10 For the Hydrogen like atom, the transition from n=3 to n=1, frequency is 192 x 1015. Then find the frequency when transition takes place from n=2 to n=1.

Q.11 At the same temperature rms speed of Hydrogen, oxygen and carbon dioxide be VH2, VO2, VCO2

Answer. VH2 > VO2 > VCO2

Q.12 Formula for Hydroxyapatite

Q.13 If ln (x+y) = 4xy, find d2y/ dx2 at x = 0.

Q. 14 The ratio of water molecules of potash alum to Mohr’s salt is

Q.15 Car A overtakes car B with relative velocity of 40 ms-1. With what velocity car A appearing in the mirror (f = 10 cm) of car N 1.9m far from it.

Q.16 Ellipse: x2/8 + y2/4 = 1 tangent at P(2nd quard) ⊥ to x+dy=0 eccentricity = e. SS’ is foci. Find (5-e2)* ΔSPS’.

Q.17 Find ∑ r2 . 20Cr.

Q.18 Which of the following will dissolve in water and give colour?
1.) Cu2Cl2
2.) CuCl2
3.) AgBr
4.) ZnCl2

Q.19 On heating novolac with formaldehyde which of the following polymers will form.

Q.20 Mean & standard deviation of 20 observations are 10 & 2.5. It is observed that one entry was taken 25 instead of 35. Find correct mean & variance.

Q.21 a + ar + ar2 + …… = 15
a2 + (ar)2 + (ar2)2 + ……. = 150. Find ar2 + ar4 + ar6 + ……

Q.22 S1: Ellingham diagram is used to check which metal to be reduced by which compound.
S2: In Ellingham diag as we move from left to right ΔS increases.

Answer. S1 is incorrect but S2 is correct.

Q.23 S1: Methyl orange is a suitable indicator for titration of strong acid and weak base.
S2: Phenolphthalein is not a suitable indicator for titration of acetic acid and NaOH.

Answer. S1 is correct but S2 is incorrect.

Q.24 Find the dimensions of p in the formula p = E L M-5G-2, where E = Energy, M = Angular Momentum, M = Mass, G = Gravitational Constant

Q.25 ((cos^2(x)+cos^4(x))/(sin^2(x)+sin^4(x)))

Q.26 Reaction of phenol with Br2 and H2O gives A reaction and reaction of phenol with Br2 and CS2 at less than 5oC gives B. Find the products A and B. JEE Main 2021 Final Answer Key (Official) for third phase has been released on 5th August 2021. Click here to view answer key. JEE Main 2021 Answer Key (Official) has been released on 29th July 2021. Click here to view answer key. JEE Main 2021 Institutional Answer Key for April session has been released for  Day 4 (Shift 1 & 2). Check below for the institutional answer key.

### Institutional Answer Key by Resonance:

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JEE Main 2021 Institutional Answer Key for March session exam has been released. Official answer key is releasing soon. Check answer key from below.

### Memory Based Answer Key (16th March- Shift 1)

Q. 1: A magnetized steel wire magnetic moment M1. If the wire is bent to form a semi-circular arc. What will be the new magnetic moment?

Q.2: Separation of sulphur & oxide are done by what method?

Q.3: The middle term in the expression (x2 +1/n2 + 2)n is?

Q.4: Which hydride of group 15 has most reducing power?

Q.5: Which is a natural polymer?

Q.6: What is the name of vitamin B12?

Q.7: A particle is moving along x-axis. x = A + Bsinωt, SHM. Find amplitude.

Q.8: Total volume of container is V, 16g O2, 44g CO2, 28g N2. Find pressure.

Q.9: Number of divisors of the form (4n+2), of the integer 240 is?

Q.10: Ozone is responsible for ?

JEE Main 2021 Institutional Answer Key has been released.  Check answer key from below.

### Memory Based Answer Key (Paper 2A)

Q. 1: The minimum number of times a fair coin need to be tossed so that probability of getting at least two head is at least 0.96 is…?

Q.2: Find the equation of normal to the curve x² = 4y which passes through the point (1,2)?

Q.3: If A+B+C=180° then find tanA+tanB+tanC=?

Q.4: Who was the designer of World Trade Center?

Q.5: Area of triangle formed by the complex number z, iz and z+iz is?

Q.6: The DE representing the family of curve Y2 (2c+x2021) where c is the positive parameter is of?

Q.7: If zand zunimodular complex number that satisfy z12 + z22 = 4 then (z1 + z1)(z2 + z2)is equal to?

Q.8: Given x=cy+bx, y=az+cx, z=bx+ay, where x, y and z are not all zero then a² + b² + c² = 2ab is equal to?

Q.9: Number of divisors of the form (4n+2), of the integer 240 is?

Q.10: The locus of the midpoint of the chord of the circle x²+y=4 which substance a right angle at the origin is?

Q.11: The point on the curve Y2 + 3x= 12y, when the tangent is vertical, is (are)?

Q.12: If B and C are square matrix of order n, and if A=B+C and BC=CB and C²=0, then for any positive integer P, AP+1=Bk[B+(P+1)C]

Q.13: The area bounded by the curve y=√x. 2y+3 =x, and x-axis in the first quadrant is?

Q.14: If f:(1,∞)–> (2,∞) is given by f(n)=n+1, the f-1(n) equals to?

Q.15: If 0< P(A) < 1, 0< P(B) < 1 and P (A⋃B) = P (A) + P(B) – P(A) P(B), then select the appropriate answer.

Q.16: If x > 1, y > 1, z > 1 are in GP, then 1 /1+lnx, 1 /1+lny, 1 /1+lnz are in _______

Q.17: If z1 and z2 are two non-zero complex number such that |z1 + z2| = |z1| + |z2|, then argz1 – argz2 is equal to?

After the successful completion of examination, the tentative answer keys has been released by the coaching institutions for April session. The provisional answer key has also released by NTA.

As per the changes made in JEE Main 2021 exam, the exam is being organised in four sessions in a year. So, according to this the answer key will be also released four times – February, March, April & in May sessions.

The answer key is a set of answers for the questions that will be asked in the exam. The answer key help the students in evaluating the right answers of the question and also helps in calculating their expected score.

Starting from the exam date till the result date, a highly pressure and tensed time is very hard to pass by students without knowing that how they have performed on exam sheet. But by evaluating answer key they can lower down their tension.

Also Check:

JEE Main 2021 Question Papers

JEE Main 2021 Cut Off

## JEE Main Answer Key Releasing Dates

Final answer key for fourth session has been released on 8th Sepember 2021. The JEE Mains answer key is released four times in a year.

The authority has published the provisional answer key for April session on 29th July 2021. Candidates are able to make suggestions or raise objections against the answer key. After the consideration of objections, the final answer key will be released by the authority.

For the first session, the answer key has been released on 1st March 2021. Likewise, for the second, third session it has been made available on 24th March 202129th July 2021. Candidates are able check the answer keys along with the images of response sheets.

With the help of answer keys, candidates are able to predict the marks they will score in the entrance exam.

• Enter application Number, password and security pin.
• The answer key of all sets will be displayed on the screen.
• Take the print copy of the answer key for future use.

Also Check:

JEE Main 2021 Rank Predictor

JEE Main 2021 College Predictor

## How to Challenge the Answer Key

Candidates are able to challenge the answer key if they are not satisfied with the answers. The challenge of JEE Main answer key is accepted through an online process only. Candidates must have to fill the application form & deposit Rs. 1000 per question to challenge the answer key before the last date of challenging. The challenges submitted by post or in person will not be accepted.

Candidates can submit the fee through Credit Card/ Debit Card, SBI Buddy and Paytm. The fee is non-refundable once paid. The final decision regarding the answer key challenge can be made by the NTA.

## JEE Main Previous Year Papers & Keys

Candidates can check the JEE Main question papers along with their answer keys for Paper 1 & Paper 2 below:

### For 2020: 2nd Session

Check JEE Main 2020 2nd session final answer key for paper I and paper II in the given table:

### For 2020: 1st Session

Check JEE Main 2020 1st session final answer key for paper I and paper II in the given table:

## Memory Based Answer Key – By Coaching Institutions

Check below memory based answer key for Jee Main April & January session released by resonance, Narayana and other coaching institutes:

### Memory Based Answer Key for 6th September 2020

Q. 1: A gas have three translation and two rotational degree of freedom. Find c∨p/ c∨v.

Q. 2: Length of clock second hand 0.1 m what is the order of its angular velocity in radian per/ sec.

### Memory Based Answer Key for 5th September 2020

Q. 1: Which is not an essentials amino acids?

1. Valine
2. Tryosine
3. Leucine
4. Lysine

Q. 2: Water vapours and water in container are in equilibrium. Some amount of glucose is added to water. What happens to the rate of evaporations?

Q. 3: How many coordination sides are there in EDTA4- in integer type?

Q. 4: If the co- ordinates of two point A and B are (√7, 0) and (-√7, 0) respectively and P is any point on the curve 9x2+16y2=144. Then find AP+PB.

Q. 5: Given that these are 7 observations 2, 4, 10, 12, 14, x, y and their mean=8 and variance= 16. The Ι x-y Ι is:

1. 2
2. 4
3. 5
4. 6

Q. 6: Which is not necessary Apparatus in acid base titration?

Q. 7: A uniform current carrying ring of mass m and radius R is connected by a mass less string. A uniform magnetic field B0 exists in the region to keep the ring horizontal. The current in the ring is:

Q. 8: If the distance of the line 2x-y+3= 0 from 4x-2y+p=0 and 6x-3y+r=0 is respectively 1/√5 and 2√5.

Q. 9: Let λ ∈ R, the system of linear equation

2x1-4x2+λx3=1

x1-6x2+x3=2

λx1-10x2+4x3=3

is 0 in constant. Find the value of λ

Q. 10: Find the magnetics moment and electronic configuration of Gd3+(Z=64) is:

Q. 11: How many isomers possible for [Pt (en)2(NO2)2] compound?

Q. 12: If the point P on the curve 4x2+5y2-20 is the farthest from the point Q (0, -4) then find PQ2

Q. 13: Find the product of the roots of equation 9x2-18 ΙxΙ + 5=0

Q. 14: If the common tangent to the parabola y2=4x and x2=4y also touches the circle  x2+y2= c2. Then find the value of c?

Q. 15: 210+29. 31,…..+2.310+ 310=A-211. Find A

### Memory Based Answer Key for 4th September 2020

Q. 1: What is the role of the CaCo3 in the extraction of iron?

1. If decomposes to form CaCo3 which acts as a flux
2. It is used a reducing agent
3. For purification of iron
4. None of these

Q. 2: Which is the following is not a method of purification of colloid?

1. Dialysis
2. Peptization
3. Electrodialysis
4. Ultrafiltration

Q. 3: A Balmer series lies in which region of the electromagnetic spectrom?

1. Ultraviolet
2. Infrared
3. Visible range
4. Microwave

Q. 4: A circular disc of mass M and radius R rotating with the speed w and another disc of the same mass M and radius R/ 2 placed coaxially on first disc. After sometime, disc 2 also attain constant speed w∨2 . Find the loss of percentage in energy.

Q. 5: Two charges 4q and -q are kept on x-axis at (-d/2,0) and (d/2,0). Then a charge +q is is moved from the origin to x=d via semi circler path. Then find the charge in its energy.

Q. 6: In maltose structure which three groups are there?

Q. 7: For the first order reaction/ 75% reaction complete in 90 min. For the same reaction 60% complete in what time?

Q. 8: Leat nitrate on heating gives A, A on cooling gives B, NO with B give C (blue solid). Find oxidation number of N in compound C.

1. +1
2. +2
3. +3
4. +4

Q. 9: Which is the following reacts with CHCl3+ KOH?

Q. 10: It is given that AB=15 and CD=10. They are parallel rods on the ground. AC and BD meet hypothetically at P. Find distance of P from the ground.

Q. 11: Element with atomic number 101 and 104 belongs to the group respectively.

1. Actinoacids and gr 4
2.  gr 4 and gr 3
3. gr 4 and gr 5
4. None

Answer: 1. Actinoacids and gr 4

Q. 12: If from point P (3,3) on the hyperbola as a normal is drawn which cuts x-axis at (9,0) on the hyperbola x2/a2-y2/b2 =1 then the value of (a2, e2) is:

Q. 13: Which represents the correct order of ionic radii?

Q. 14: 76% people read newspaper A and 63% read newspaper B then the probability of people who read both of the newspapers are?

Q. 15: A solution contains two volatile solvents of 1 mole of n- hexane and 3 mole of n- heptane. In this case, vapour pressure of the solution 550 mm Hg. If 1 mole of 1- Heptane if further added to solution. The vapour pressure increases by 10 mm Hg. Find out the pressure of pure n- Heptane solution?

### Memory Based Answer Key for 3rd September 2020

Q.1: Thermal power plant cause

1. Acid rain
2. Ozone layer depletion
3. baby syndrome
4. eutrophication

Aswer: 1. Acid rain

Q. 2: No. of P=o, P-oh, P-o-p bond is pyrophosphoric acid?

Q. 3: If a variable place in 3-0 space moves in such a way that the sum of its intercepts on the x and y-axis exceeds, the reciprocal of its intercept on the Z-axis is by 2, then all such plane will pass through  the point:

1. (1/2, 1/2, -1/2)
2. (1/2, 1/2, 1/2)
3. (1/2, -1/2, -1/2)
4. (1/2, -1/2, 1/2)

Q. 4: A bag is contain 6 red balls and 10 orange balls. 3 balls are drawn from it one by one randomly without replacement. if the third ball drawn is red, then the probably that the first two balls are green is:

1. 3/7
2. 9/149
3. 9/56
4. 3/8

Q. 5: If the first term is 3 and sum of the first 25 terms is equal to the sum of the next 15 terms then find the common difference?

Q. 6: Let the data 4, 10, x, y, 27 be in increasing order. If the medium of data is 18 and its mean deviation about mean is 7.6, then the mean of this data is:

1. 7
2. 16
3. 16.5
4. 15.5

Q. 7: Let the ellipse, x2/ a2, y2/ b2 = 1, if a > b pass through the point (2,3) and have eccentricity equal to 1/2, then the equation of normal to the ellipse to (2,3) is:

Q. 8: Gas released When Ay, Pt dissolved in Aqua region

1. NO
2. N2
3. N2O3
4. N2O5

Q. 9: Number of isomers including stereoisomers of simplest optically active alkene after hydrogenation H2/ Ni and monohalogenation with HX

Q.10: Min bond length

1. NO2+
2. NO+
3. NO
4. NO

Q. 11: Find % w/w of H2O in solution containing glucose with Xgluc =0.1

1. 20%
2. 47.3%
3. 25.3%
4. 27.4%

Q. 12: Most basic amino acid is?

Q. 13: A solution of 4% X and another solution having 12% Y (both soliton have same solvent). If molar mass X is A then molecular mass of Y is:

1. 3A
2. A
3. A/2
4. 2A

Q. 14: If the centre of circle lies on x+y=2 and it touches the line x=3 and y=2, find the diameter of the circle?

Q. 15: A dice is thrown twice. Sum of both the observation is a multiple of 4. Find the probability that 4 appeared at at least once?

Q. 16: If the wavelength on incident radiation changes from 500nm to 200nm, then the maximum kinetic energy increases to three times. Find the work function?

Q. 17: Pressure inside soap bubble is 1.01 and 1.02 atmosphere. The ratio between their volume is:

1. 102:101
2. (102)3: (101)3
3. 8:1
4. 2:1

Q. 18: A ballon contain He gas at ‘T’ get burst then it is:

1. Reversible isothermal
2. Irreversible isothermal

Q. 19: Boiling point of water is 273k, then the boiling point of H2S is:

1. >373k
2. <373k
3. 373k
4. 373>x>300k

Q. 20: Find the atomic number of unnilennium

1. 101
2. 107
3. 109
4. 119

Q. 21: How glycerol can be purified

1. Distillation under reduced pressure
2. Fractional distillation
3. Differential extraction
4. steam distillation

Answer: 1. Distillation under reduced pressure

### Answer Key for 2nd September 2020

Q. 1: Which of the following is different sol?

1. butter
2. paints
3. gen stone
4. cake

Q. 2: Find the length and the foot of perpendicular from the point of (1, 3/2,2) to the plane 2x-2y+4z+5=0.

Q. 3: Which property has different order wrt others?

2. Electronegativity
3. Ionisation energy
4. Electrongain Enthalpy

Q. 4: What is structure of Dettol?

Q. 5: If F=ma and mass (M) is defined as α and acceleration (a) is defied as β. The find the new SI unit of F.

Q. 6: F(x)=-(3/4)X2-8X3-42/5X2+105.  calculate local maxima and local minima.

### Answer Key for 1st September 2020

Q. 1: A boy can throw a stone up to a maximum height of 10m. The maximum horizontal distance that the boy can throw the same stone will be-

1. 20m
2. 20?2m
3. 10m
4. 10?2m

Q. 2: Where is Notre Dame Cathedral located?

Q. 3: An equation of plane parallel to the plane x-2y+2z-5 =0 and at a unit distance from the origin is-

1. x-2y+2z-5=0
2. x-2y+2z-3=0
3. x-2y+2z+1=0
4. x-2y+2z-1=0

Q. 4: A Carnot engine whose efficiency is 40% takes in the heat from a source maintained at a temperature of 500 k. It is desired to have an engine of efficiency of 60%. Then the intake temperature from the same exhaust (sink) temperature must be-

1. 600 k
2. Efficiency of Carnot cannot be made larger than 50%
3. 1200 k
4. 750 k

Q. 5: If the line 2x=y=k passes through the point which divides the line segment joining the points (1,1) and (2,4) the ratio 3:2, then k equals-

1. 11/15
2. 29/5
3. 5
4. 6

Q. 6: Where does the president of USA lives?

Q. 7: A thin liquid film formed between a U- shaped wire and a light slider supports and weight of 1.5×10-2N. The length of the slider is 30 cm and its weight negligible. The surface tension of the liquid film is-

Q. 8: Where Bara Imambra is located?

Q. 9: Downing street is whose residence?

Answer: Downing Street is the residence of the prime minister of the United Kingdom (the lord of the treasury).

Q. 10: Where is Badrinath located?

Q. 11: Which colour represents equality?

Q. 12: Where is leaning tower located?

Q. 13: What does shaft represent?

Q. 14: If pth, nth, rah terms of G.P. then p,q,r are in?

Q. 15: Given 30 observation then 10 observations are 1/2-d, other 10 observations are d and remaining 10 observations are 1/2+d, the variance is given 4/3

Q. 16: Draw a highway road diagram with car and truck in opposite directions

Q. 17: F (x+y)= f(x).f(y)x, y€N f(1)=2 then sigma k= 1 to 50 f(4+k)=

Q. 18: Free fall of an object in vacuum in the case of motion

Q. 19: Who designed IIM?

Q. 20: Which colour reflects the maximum light?

Q. 21: a1 a2 a3 a4 a5 are ap. sum of the term is equal to 30. product of the term is equal to 3840. find product of first and last term

### For 2018:

 Exam Date Question Papers 8th April 2018 SET A | SET B | SET C | SET D 15th April 2018 Morning | Evening 16th April 2018 Morning

### For 2017:

Candidates may also check the JEE Main question papers from here:

## JEE Main Answer Key (Institutional)

Candidates can check last year JEE Main answer key prescribed by Sarvgyan and various other coaching institutions from here for CBT exam:

### JEE Main 2019 Institutional Answer Key (January Session)

In the table given below we have provided the answer keys for various shifts:

### JEE Main 2018 Institutional Answer Key (April Session)

 Institution Question Paper Answer Keys Resonance 15th April | 16th April 15th April | 16th April RAO IIT 15th April 15th April Ask IITians 15th April (Morning Shift) 15th April (Morning Shift)

Check here the answer keys for offline exam of JEE Main:

## JEE Main Question Paper Solutions

Candidates may also check the last year JEE Main question paper solutions from here:

 Institute Downloads JEE Main Question Paper Solutions by Vidyamandir Classes SET B – Physics  | Chemistry | Mathematics JEE Main Question Paper Solutions Solutions by Aakash Institute SET A | SET B | SET C | SET D JEE Main Question Paper Solutions by Allen Kota SET C – Physics  | Chemistry | Mathematics JEE Main Question Paper Solutions by Motion IIT-JEE SET A | SET B | SET C | SET D JEE Main Question Paper Solutions by Career Point SET A | SET B | SET C | SET D JEE Main Question Paper Solutions by IITians PACE Academy SET A | SET B | SET C | SET D JEE Main Question Paper Solutions by Sri Chaitnaya SET A | SET B | SET C | SET D JEE Main Question Paper Solutions by Vibrant Academy SET A | SET B | SET C | SET D JEE Main Question Paper Solutions Solutions by Resonance SET A | SET B | SET C | SET D JEE Main Question Paper Solutions Solutions by Rao IIT Academy SET A | SET B | SET C | SET D JEE Main Question Paper Solutions Solutions by Vidyalankar SET A | SET B | SET C | SET D JEE Main Question Paper Solutions Solutions by T.I.M.E. SET A | SET B | SET C | SET D JEE Main Question Paper Solutions Solutions by Narayana SET A | SET B | SET C | SET D

Note: JEE main answer key prepared by different coaching institutes are correct to their knowledge. Sarvgyan will not be responsible for any misprint, wrong answer and any sort of variation in the answer key of different coaching institutes.

Candidates having any doubt for JEE Main Answer Key 2021, can drop comments in the comment box.

1. Chethan says:

Sir you repeated your uploaded physics paper in chemistry in 25th july 1st shift….

2. Tina Jangid says:

Can i know the cutoff this year
Please sent me the cutoff list

3. Abhishek says:

NEET Application date & link ???

• Sarvgyan Team says:

NEET 2021 Application Form link will be made available after the confirmation from authority, so stay tuned and keep checking our articles for latest updates. GD Goenka University applications closing Today