Higher Engineering Mathematics

(Greg DeLong) #1
INTEGRATION USING ALGEBRAIC SUBSTITUTIONS 395

H


  1. The electrostatic potential on all parts of a
    conducting circular disc of radiusris given
    by the equation:


V= 2 πσ

∫ 9

0

R

R^2 +r^2

dR

Solve the equation by determining the
integral.
[
V= 2 πσ

{√
(9^2 +r^2 )−r

}]


  1. In the study of a rigid rotor the following
    integration occurs:


Zr=

∫∞

0

(2J+1)e

−J(J+1)h^2
8 π^2 Ik T dJ

DetermineZr for constant temperatureT
assumingh,Iandkare constants.[
8 π^2 IkT
h^2

]


  1. In electrostatics,


E=

∫π

0


⎪⎨

⎪⎩

a^2 σsinθ

2 ε

√(
a^2 −x^2 −2axcosθ

)dθ


⎪⎬

⎪⎭

where a,σandεare constants,xis greater
than a, andxis independent ofθ. Show that

E=

a^2 σ
εx
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