Important Formulas for JEE Main 2020: Subject-wise list

JEE Main 2020- Joint Entrance Examination-Mains 2020 organized by the NTA (National Testing Agency) for students applying to B.E/ B. Tech, B. Arch and B. Planning programs. The JEE Main 2020 conducted in April 2020 has been postponed because of the COVID-19 outbreak until further notice by the MHRD officials. In the meantime, students can revise some of the important formulas for the JEE Main 2020 to continue with their practice.

Revision is the most important aspect of preparing for any exam. Students can take our study plan for the JEE Main 2020. Candidates can prepare flashcards, make a last-minute revision plan, revise all the important formulas. Having memorized all the important formulas will lead to the candidate acing the JEE Main 2020 with a good score.

Importance of Important Formulas

While preparing for the exam make notes for the important formulas for each and every subject separately. These handy notes help in focusing on the concepts. The Important Formulas can help candidates in:

• Saving time in the exam
• Making the calculations easier
• Reduce the risk of mistakes
• Better Preparation for the exam

Quick Fact: The NTA has declared a new exam pattern that adds a new Numeric value-based problem to each section.

JEE Main 2020 Highlights

JEE Main 2020 Important Formulas

JEE Main 2020 paper available in 3 mediums Hindi, English, and Gujrati consists of three sections:

• Mathematics
• Chemistry
• Physics

The candidates can refer to the subject-wise important formulas for the JEE Main 2020 below:

Important Formulas for Physics

• The energy of electric dipole is given by U = – p.E.
• The energy of a magnetic dipole is U = – μ .B C.
• Electric Charge : Q = ± ne (e = 1.60218 × 10-29 C)
• SI unit of Electric Charge is Coulomb ©
• Coulomb’s Law : Electrostatic Force (F) = k[q1q2/r2] and,
• In Vector Form :
  • →F=k(q1q2)×→r/r3
    • Where, q1 and q2 = Charges on the Particle,
    • r = Separation between them,
    • →r = Position Vector,
    • k = Constant = 14πϵ0=8.98755×109Nm2C2
• Electric Current :
  • The current at Time t : i=limΔt→0 ΔQ/Δt= dQ/dT
    • Where Δ Q and Δ T = Charges crosses an Area in time Δ T
    • SI unit of Current is Ampere (A) and 1A = 1 C/s
• Average current density:
  • →j=Δi/Δs
  • j=limΔs→0 Δi/Δs=di/dS ,
  • j=Δi/ΔScosθ
    • Where, Δ S = Small Area,
    • Δ i = Current through the Area Δ S,
    • P = Perpendicular to the flow of Charges,
    • θ = Angle Between the normal to the Area and the direction of the current.
• Kirchhoff’s Law: Law of Conservation of Charge: I3 = I1 + I2
• Resistivity : ρ(T)=ρ(T0)[1+α(T−T0)]
•  Resistance:
  • R (T) =R (T0) [1+α (T−T0)]
    • Where, ρ (T) and ρ (T0) = Resistivity at Temperature T and T0 respectively,
    • α = Constant for given material.

• Lorentz Force :
  • →F=q[→E+(→v×→B)]
    • Where, E = Electric Field,
    • B = Magnetic Field,
    • q = Charge of Particle,
    • v = Velocity of Particle.
• Magnetic Flux:
  • Magnetic Flux through Area dS = ϕ=→B⋅d → S= B⋅dS Cos θ
    • Where, d→S = Perpendicular vector to the surface and has a magnitude equal to are Ds,
    • →B = Magnetic Field at an element,
    • θ = Angle Between →B and d→S,
    • SI unit of Magnetic Flux is Weber (Wb).
• Straight line Equation of Motion (Constant Acceleration):
  • v=u+at
  • s=ut+1/2at2
  • 2as=v2−u2
• Gravitational Acceleration Equation of Motion:
  • Motion in Upward Direction:
    • v= u-gt
    • y=ut−1/2gt2
    • −2gy=v2−u2
  • Motion in Downward Direction:
    • v=u+gt
    • y=ut+1/2gt2
    • 2gy=v2−u2
• Projectile Equation of Motion:
  • Horizontal Range (R) = u2sin2θ/ g
  • Time of Flight (T) = 2uSinθ/ g
  • Maximum Height (H) = u2sin2θ/ 2
  • Where,
    • u = initial velocity,
    • v = final velocity,
    • a = constant acceleration,
    • t = time,
    • x = position of particle.
• Universal Law of Gravitation:
  • Gravitational force →F=G[Mm/r2]^r
  • Where, M and m = Mass of two Objects,
    • r = separation between the objects,
    • ^r = unit vector joining two objects,
    • G = Universal Gravitational Constant
      • [G=6.67×10−11N⋅m2/Kg2]
• Work Done by Constant Force:
  • Work Done (W) = →F⋅→S=∣→F∣ ∣→S∣ cosθ,
    • Where, S = Displacement along a straight line,
    • F = applied force,
    • θ = Angle between S & F.
  • It is a scalar quantity and the Dimension of work is [M1 L2 T-2], SI unit of Work is the joule (J) and 1J=1N⋅m=Kg⋅m2/ s2
• Kinetic Friction:
  • fk = µk · N
  • Maximum Static Friction (Limiting Friction): fmax = µs · N,
    • Where, N = Normal Force,
    • µk = Coefficient of Kinetic Friction,
    • µs = Coefficient of Static Friction.
• Simple Harmonic Motion:
  • Force (F) = – k x and k = ω2 m
    • Where, k = Force Constant,
    • m = Mass of the Particle,
    • x = Displacement and ω2 = Positive Constant.

Important Formulas for Chemistry

• T(K)=T(⁰C) + 273.15
• Molarity (M)= No. of Moles of Solutes/ Volume of Solution in Liters

Unit: mole/ L

• Molality (m)=
  • No. of Moles of Solutes/ Mass of solvent in kg

Molecular Mass= 2x vapor density

• Atomic number=
  • No. of protons in the nucleus = No. of electrons in the nucleus
• Mass number=
  • No. of protons + No. of neutrons C= vλ
• Boyle’s Law:
  • P1V1 = P2V2 (at constant T and n)
• Charle’s Law:
  • V1/ T1 = V2/ T2 (at constant P and n)
• Enthalpy:
  • H = U + pV
• First Law of Thermodynamics:
  • ΔU = q + W
• Ohm’s Law:
  • V = RI where, R = ρ ι/a
• Faraday’s First Law of Electrolysis:
  • M = Zit
    • M = mass of substance deposited
    • Z= Electrochemical Equivalent
    • I = current,
    • t= time
    • Z= Atomic Mass/ n x F
• Faraday’s Second Law of Electrolysis:
  • M1/ M2 = E1/E2 ,
    • Where E = equivalent weight
• Freundlich Adsorption Isotherm:
  •  [x/m]-Kp (1/n); n>=1
• General Electronic Configuration:
  • ns1-2

Important Formulas for Mathematics

The general form of Complex numbers x + is where x is Real part and y is an Imaginary part.

• Sum of nth root of unity is zero
• Product of nth root of unity (–1)n–1
• Cube roots of unity are 1, ω, ω2
  • |z1+z2|<=|z1|+|z2|; |z1+z2|>=|z1|-|z2|; |z1-z2|>=|z1|-|z2|
• If three complex numbers z1, z2, z3 are collinear then,
  • [z1 z1 1
  • z2 z2 1
  • z3 z3 1] = 0

• If ΣCosα = ΣSinα = 0, ΣCos2α = ΣSin2α = 0,
• ΣCos2nα = ΣSin2nα = 0,
• ΣCos2α = ΣSin2α = 3/2
• ΣCos3α = 3Cos(α + β + γ),
• ΣSin3α = 3Sin(α + β + γ)
• ΣCos(2α – β – γ) = 3,
• ΣSin(2α – β – γ) = 0,
• a3 + b3 + c3 – 3abc = (a + b + c) (a + bω + cω2) (a + bω2 + cω)
• Standard form of Quadratic equation:
  • ax2 + bx +c = 0
  • Sum of roots = -b/a,
  • Product of roots discriminate = b2 – 4ac If α, β are roots then Quadratic equation is x2 – x(α + β) + αβ = 0
• Number of terms in the expansion: (x+a)n is n+1
  • Any three non coplanar vectors are linearly independent
• A system of vectors ā1, ā2,….ān are said to be linearly dependent,
  • If there, x1ā1+x2ā2+….+xnan=0
  • At least one of xi ≠0, i=1, 2, 3….n
  • And determinant = 0
• Torque: The torque or vector moment or moment vector (M) of a force (F) about a point (P) is defined as:
  • M = r×F
  • Where, r is the vector from the point P to any point A on the line of action L of F.
• a,b,c are coplanar then [abc]=0
• If i,j,k are unit vectors then [i j k] = 1
• If a,b,c are vectors then [a+b, b+c, c+a] = 2[abc]
• (1 + x)n – 1 is divisible by x and (1 + x)n – nx –1 is divisible by x2
• If nCr-1 nCr nCr+1 are in A.P (n–2r)2 =n + 2

Every year the number of candidates apply for the JEE Main exam, because of this competition has become so high. To crack JEE Main with high score candidates are advised to keep a handy note of these important formulas for JEE Main. Here we have provided out the most useful JEE Main important formulas which can be helpful for the preparation of the exam from all 3 subjects- Physics, Chemistry, and Mathematics. When candidates prepare for JEE Main exam, they find Physics as the toughest section because of the long derivations.