Q73.The sum ∑20k=1(1 + 2 + 3 + … + k) is ___________.
What This Question Tests
This numerical question involves calculating the sum of a series where each term is the sum of the first k natural numbers, which simplifies to the sum of squares formula.
Concepts Tested
Formulas Used
Σk = n(n+1)/2
Σk² = n(n+1)(2n+1)/6
📚 NCERT Sections This Tests
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.
1.18 — A Point Charge Of 2.0 Mc Is At The Centre Of A Cubic Gaussian
Physics Class 11 · Chapter 1
1.18 A point charge of 2.0 mC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?
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.
📋 Question Details
- Chapter
- Sequences & Series
- Topic
- Sum of series
- Year
- 2020
- Shift
- 08 Jan Shift 1
- Q Number
- Q73
- Type
- Numerical
- NCERT Ref
- Class 11 Mathematics Ch 9: Sequences and Series
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