Q66.If the sum 3 + 5 + 7 + .... .+ up to 20 terms is equal to 21k , then k is equal to 12 12+22 12+22+32 (1) 240 (2) 120 (3) 60 (4) 180
What This Question Tests
This question requires identifying the general term of a series, simplifying it using the formula for the sum of squares, and then finding the sum using the telescoping series method, potentially requiring inference for a numerical constant.
Concepts Tested
Formulas Used
ฮฃr^2 = r(r+1)(2r+1)/6
1/(r(r+1)) = 1/r - 1/(r+1)
๐ NCERT Sections This Tests
2.2 โ A Regular Hexagon Of Side 10 Cm Has A Charge 5 Mc At Each Of Its
Physics Class 11 ยท 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.
3.20 โ For The Decomposition Of Azoisopropane To Hexane And Nitrogen At 543
Chemistry Class 11 ยท Chapter 3
3.20 For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained. t (sec) P(mm of Hg) 0 35.0 360 54.0 720 63.0 Calculate the rate constant.
2.4 โ A Spherical Conductor Of Radius 12 Cm Has A Charge Of 1.6 ร 10โ7C
Physics Class 11 ยท Chapter 2
2.4 A spherical conductor of radius 12 cm has a charge of 1.6 ร 10โ7C distributed uniformly on its surface. What is the electric field (a) inside the sphere (b) just outside the sphere (c) at a point 18 cm from the centre of the sphere?
๐ Question Details
- Chapter
- Sequences & Series
- Topic
- Summation of series
- Year
- 2014
- Shift
- 09 Apr Online
- Q Number
- Q66
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 9: Sequences and Series
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