IIT JEE 2009 P1 Q43

Three Concentric metallic spherical shells of radius R, 2R, 3R are given charges Q1,Q2, Q3 respectively. It is found that the surface charge densities of the outer surface of theshells are equl . Then the ratio of the charges given to the shells Q1:Q2:Q3 is

A) 1:2:3
B) 1:3:5
C) 1:4:9
D) 1:8:18

12 Answers

62
Lokesh Verma ·

[url=http://iitjee2009solutions.targetiit.com]Solution Key with Question Paper of 2009 IIT JEE[/url]

1
voldy ·

isn't the answer C ?????

11
virang1 Jhaveri ·

Let the charge density be k
Q/A = K
Q/4∩r2 = k
now let 4∩ be C
Q = CK*r2
Q1 = C*K *R2
Q2 = C*K*4R2
Q3 = C*K*9R2
Q1:Q2:Q3

Therefore the rite option is C 1: 4 : 9

1
ANKIT MAHATO ·

conceptual error virag !

1
voldy ·

what's wrong ? bolo na ?

1
kamalendu ghosh ·

Yes ans is b

1
kamalendu ghosh ·

NOTE CONCENTRIC spheres

1
rahul wadhwani ·

its B

1
Vivek ·

@srinath,virang

it says outer surface charge densities

1
~AjInKyA~ ·

B

1
Shreyan ·

can anyone explain why its B???

9
Celestine preetham ·

its B

note that outer charges are Q1,Q1+Q2 ,Q1+Q2+Q3

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