Q65.If the sum of the series 12 + 2 ⋅22 + 32 + 2 ⋅42 + 52+ ... 2.62 + … upto n terms, when n is even, is n(n+1)22 then the sum of the series, when n is odd, is (1) n2(n + 1) (2) n2(n−1) 2 (3) n2(n+1) (4) n2(n −1) 2
What This Question Tests
The question requires careful observation of the given series pattern and utilizing the provided sum formula for even 'n' to deduce the sum for odd 'n' by relating S_n (odd) to S_{n+1} (even).
Concepts Tested
Formulas Used
S_n = S_{n+1} - T_{n+1}
📚 NCERT Sections This Tests
12.5 — A Hydrogen Atom Initially In The Ground Level Absorbs A Photon,
Physics Class 12 · Chapter 12
12.5 A hydrogen atom initially in the ground level absorbs a photon, which excites it to the n = 4 level. Determine the wavelength and frequency of photon.
12.8 — A 12.5 Ev Electron Beam Is Used To Bombard Gaseous Hydrogen At
Physics Class 12 · Chapter 12
12.8 A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. What series of wavelengths will be emitted?
2.2 — A Regular Hexagon Of Side 10 Cm Has A Charge 5 Mc At Each Of Its
Physics Class 11 · Chapter 2
2.2 A regular hexagon of side 10 cm has a charge 5 mC at each of its vertices. Calculate the potential at the centre of the hexagon.
📋 Question Details
- Chapter
- Sequences & Series
- Topic
- Summation of series
- Year
- 2012
- Shift
- 26 May Online
- Q Number
- Q65
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 9: Sequences and Series
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