RankLab
Back to Questions
MathsHardMCQ2019 · 12 Apr Shift 2

Q65.If 20C1 + (22) 20C2 + (32) 20C3+. . . . . +(202) 20C20 = A(2β), then the ordered pair (A, β) is equal to JEE Main 2019 (12 Apr Shift 2) JEE Main Previous Year Paper (1) (380, 19) (2) (420, 18) (3) (420, 19) (4) (380, 18) − 3 ) 6 is equal to x2

What This Question Tests

This question requires knowledge of specific summation identities involving binomial coefficients, particularly for sums of the form Σ r² * nCr, which can be derived using differentiation or combinatorial arguments.

Concepts Tested

Binomial coefficient identitiesSummation techniques

Formulas Used

Σ r * nCr = n * 2^(n-1)

Σ r^2 * nCr = n(n+1)2^(n-2)

📚 NCERT Sections This Tests

13.5The Q Value Of A Nuclear Reaction A + B ® C + D Is Defined By

Physics Class 12 · Chapter 13

71% match

13.5 The Q value of a nuclear reaction A + b ® C + d is defined by Q = [ mA + mb – mC – md]c2 where the masses refer to the respective nuclei. Determine from the given data the Q-value of the following reactions and state whether the reactions are exothermic or endothermic. (i) 11 H+13 H →12 H+12 H (ii) 126 C+126 C →1020 Ne+ 24 He Atomic masses are given to be m ( 12 H ) = 2.014102 u m ( 13 H) = 3.016049 u m ( 126 C ) = 12.000000 u m ( 1020 Ne ) = 19.992439 u

13.2Obtain The Binding Energy Of The Nuclei 5626Fe And 20983 Bi In Units Of

Physics Class 12 · Chapter 13

70% match

13.2 Obtain the binding energy of the nuclei 5626Fe and 20983 Bi in units of MeV from the following data: m ( 5626Fe ) = 55.934939 u m ( 20983 Bi ) = 208.980388 u

5.28How Many Ions Are Produced From The Complex Co(Nh3)6Cl2 In Solution?

Chemistry Class 11 · Chapter 5

69% match

5.28 How many ions are produced from the complex Co(NH3)6Cl2 in solution? (i) 6 (ii) 4 (iii) 3 (iv) 2 139 Coordination Compounds Reprint 2025-26