Details - JEE Main 2021, Login, Application Form, Correction, Admit Card, Withdraw Form Post Exam - Answer Key, Analysis, Response Sheet, Result Preparation - JEE Main 2021 Question Papers, Exam Pattern, Syllabus, Mock Test, Sample Paper, Previous Year Question Papers, Physics Notes, Chemistry Notes

JEE Main 20 Jul 2021 Question Paper with Answer Key – The official JEE Main answer key 2021 is available at jeemain.nta.nic.in. Based on the official answer key, JEE Main 2021 result shall be prepared. Download here JEE Main 2021 answer key and question paper for 20 July 2021 shift 1 and 2. The provided JEE Main 2021 question paper and answer key are unofficial and memory-based. They have been prepared by the coaching institutes and exam experts on the basis of questions collected by the students who appeared for the exam. Know more details on JEE Main 20 July 2021 Question Paper with Answer Key from this page.

JEE Main 2021 Answer Key by Resonance

## JEE Main 20 Jul 2021 Question Paper with Answer Key

#### JEE Main 2021 Answer Key for 20 July – Shift 2

Ques. ______ + Formaldehyde = Bakelite

Ans. Novolac

Ques. Which of the gas stops Photosynthesis?

Ans. Nitrogen Dioxide (NO₂)

Ques. What is the hybridization of NO2+.

Ques. In Nitration, HNO₃ and H₂SO₄ act as?

Ans. HNO₃ : Base & H₂SO₄: Acid

Ques. Which of the following does not have a magnetic moment of 1.73?

Ques. Rate of hydrolysis:ester, acid chloride, acid anhydride

Ans. Acid Chloride > Acid anhydride > Ester

Ques. A particle has 4 times its initial kinetic energy. Find the percentage change in momentum?

Ans. 100%

Ques. Find work done in the process A → B (isothermal) by gas

Ans. 200 In2

Ques.

Ans. (A) part

Ques. A body rotating have an angular velocity of 300 rpm and its angular acceleration is π / 20 (rad / s) resolutions done by this particle in 10 sec is

Ans. 205 / 4 (rev)

Ques. A body is under the influence of a force such that it delivers a constant power p. The variation os position with time of body as:

Ans. t 3/2

Ques. A solid cylinder and ring are released from rest in top of the inclined plane. Find ratio of these velocities when they reach bottom, assuming pure rolling.

#### JEE Main 2021 Answer Key for 20 July – Shift 1

Ques. A butterfly was flying in North East Direction with velocity of 4√2 m/s with respect to wind. Wind is blowing from north to south with a speed of 1 m/s. Find the displacement of bird in three seconds.

Ans. 15 m, 37° North to East

Ques. Tension in a spring is T1 when length is L1 and the tension is T2 and when its length is T2. The natural length of the spring is

Ans.

Ques. An alpha particle and a deutron enter a region of magnetic field which is perpendicular to their velocity. If both their kinetic energies are equal, then find the ration of the radii.

Ans. 1:√2

Ques. A travelling wave moving with velocity v. The equation of wave at two different instants t = 0 and t = 3 is given by y = 1 / 1+x2  and y = 1 / 1 (x+1)2 respectively. Find the speed of v of the wave (y is in mm, x is in cm).

Ans. ⅓ cm/s

Ques. Two charges are kept at a fixed distance from each other. The sum of both charges is Q. What should be the charge on each of them in order to maximise force between them.

Ans. Q/2, Q/2

Ques. A person is standing on weighing machine and is slowly taken from the surface of Earth to the surface of moon. Which of the following graphs describes the variation of “Reading of weighing machine” with respect to its distance from Earth’s surface.

Ans.

Ques. A rod moving from 0 to 2b magnetic field 0 to b, 3 graphs given identify them. Electric flux, Power dissipated, emf?

Ques. Find I2

Ans. 3 lone pairs

Ques. The difference in energy

Ans. 25 mA

Ques. Azimuthal quantum number of valence electrons of Ga+1 (Atomic Number of Ga=31)

Ans. I = 0

Ques. Vapour pressure of benzene and methylbenzene are 70 and 20 respectively. Both are equimolar mixture. Find the mole fraction of benzene in vapor phase?

Ans. 0.77

Ques. The difference in energy between the 2nd and 3rd orbit of He+ ion will be:

Ans. 7.5 ev

Ques. Which of the following can be purified using fractional distillation?

Ans. Zinc (Zn)

Ques. Orion is:

Ans. Polyacrylonitrile

Ques. 10000 kJ of energy is needed per day and heat of combustion of glucose is 2700 kJ / mol. Then, find grams of glucose needed.

Ans. 666 grams

Ques.

Ans. (b) part

Ques. Organic Compound A with CHCl₃ / KOH gives product B which can be decomposed by C.

Ans. A=Primary Amine, B = Isonitrile

Ques. s-block element having formula of Oxide MO2 and yellow colour:

Ans. K

Ques.

Ans.

Ques. Structure of ruhemann’s purple from ninhydrin test

Ques. What is hybridisation of XeOF4?

Ans.

Ques. Reason for change of dihedral angle of H2O2 when changes from gas to solid.

Ans. Hydrogen Bonding

Ques.

Ans. 11

Ques.

Ans.

Ques.

Ans. (A) part

Ques. From a team of 15 players, 6 are bowlers, 7 are batsmen, 2 are wicketkeepers. Find the number of ways to form a team of II players having at least 4 bowlers, 5 batsmen and 1 wicket keeper.

Ans. 777

Ques. The word EXAMINATION is given: then the Probability that the M is at the 4th place is:

Ans. 1/11

Ques.

Ans. 10 + In 2

Appeared for JEE Main on 20 July 2021? Then you can help us curate the memory-based questions and answers by submitting the questions asked in the exam. Just click on the button below to submit your questions and / or answers.

### How to Calculate Scores Using JEE Main 20 July 2021 Answer Key?

The candidates who have appeared in the exam can get an estimate about their scores in JEE Main using JEE Main 20 July 2021 answer key. Check the steps given below to calculate the marks.

3rd step: Then, use the marking scheme to calculate the scores.

4th step: Write down the number of correct answers and incorrect answers.

5th step: Now, calculate the marks using the marking scheme given below.

Marking Scheme

The scores obtained after following the marking scheme given above will be their probable scores.

### JEE Main 20 Jul 2021 Question Paper

Along with the answer key, many coaching institutes also release JEE Main question paper. These question papers are memory-based. This means that the questions present in the question paper have been specified according to the analysis of the candidates about the exam. The memory-based question papers are released on the same day of the exam.

Some of the coaching institutes who release JEE Main question paper are:

• Allen
• Aakash
• Resonance
• Resonance
• Motion IIT JEE

NTA also publishes the official question paper along with the answer key. The candidates can use JEE Main 2021 question paper with the answer key to calculate the scores.

NTA releases the official answer key after the completion of each session at the official website. Check the steps to download the official answer key.

1st step: Go to the official website, jeemain.nta.nic.in.

3rd step: Now, a login window will open. Here, enter the application number and password / date of birth.

4th step: After entering the details, click on the ‘Sign-in’ button.

### JEE Main 2021 Exam Pattern

Check the exam pattern of JEE Main 2021 given below.

JEE Main 2021 is a computer-based test (except drawing test in B.Arch)3 hours are given to the candidates to complete the exam. The test has multiple-choice questions and numerical value type questions.

Check the distribution of questions paper-wise given below.

B.E / B.Tech

B.Arch

B.Planning

### Previous Years JEE Main Cut-Off

JEE Main cut-off is released category-wise along with the result. The cut-off scores are basically the minimum scores required by a candidate to appear for JEE Advanced. Every candidate who appears for the exam is allotted a rank.

Check the previous years JEE Main cut-off given below.

### JEE Main 2021 Result

The candidates can check JEE Main 2021 result at jeemain.nta.nic.in. The result is compiled on the basis of the final answer key.

• To check the result, enter the application number and date of birth.
• No scorecard will be dispatched to the candidates. It has to be downloaded from the official website only.
• There is no provision for re-evaluation / re-checking of the result.
• The raw marks obtained by the candidates in different sessions / shift shall be converted to NTA score.
• According to the NTA score, All India Rank (AIR) will be calculated. AIR is calculated after the conduct of the exam for all sessions.

## FAQs on 20 July 2021 Answer Key

Ques. Can I challenge the unofficial answer key?

Ans. No, you cannot challenge the unofficial answer key if there is any error in it. These keys are based on the memory-based questions submitted by the students.

Ques. When will the official JEE Main 2021 answer key be released?

Ans. The official answer key will be released once the exam for all the shifts of the July session is over.