Solutions: Mid semester exam 2014 - edX · Solutions: Mid semester exam 2014 Q1 PART A Cartesian:...

2
Solutions: Mid semester exam 2014 Q1 PART A Cartesian: = 2 ! + Cylindrical: = 2 ! Q1 PART B 2 + 2 Q1 PART C 4 ! Q2 PART A 3 ! Q2 PART B 36 Q3 PART A = 0 < = ln ! ! < < = ln ! ! >

Transcript of Solutions: Mid semester exam 2014 - edX · Solutions: Mid semester exam 2014 Q1 PART A Cartesian:...

Page 1: Solutions: Mid semester exam 2014 - edX · Solutions: Mid semester exam 2014 Q1 PART A Cartesian: ∇!=2! !!!+!! Cylindrical: ∇!=2!!!! Q1 PART B ! 2 + 2! Q1 PART C 4!"!! Q2 PART

Solutions: Mid semester exam 2014 Q1 PART A

Cartesian: ∇𝑉 = 2𝑉! 𝑥𝐱+ 𝑦𝐲

Cylindrical: ∇𝑉 = 2𝑉!𝑠𝐬 Q1 PART B

𝛼2 +

2𝛽

Q1 PART C

4𝛼𝜋𝑅! Q2 PART A

−3𝜋𝑅! Q2 PART B

36𝜋 Q3 PART A

𝐄 = 0                        𝑟 < 𝑎

𝐄 =𝑘 ln 𝑟𝑎𝑟!𝜀!

 𝐫                        𝑎 < 𝑟 < 𝑏

𝐄 =𝑘 ln 𝑏𝑎𝑟!𝜀!

 𝐫                        𝑟 > 𝑏

Page 2: Solutions: Mid semester exam 2014 - edX · Solutions: Mid semester exam 2014 Q1 PART A Cartesian: ∇!=2! !!!+!! Cylindrical: ∇!=2!!!! Q1 PART B ! 2 + 2! Q1 PART C 4!"!! Q2 PART

Q3 PART B

𝐄 =−𝐴𝑎!

4𝜀!  

1𝑧! + 𝑎! !/! 𝐲                      

Q3 PART C

𝐄 =𝛼4𝜀!

 𝑠!𝑧

𝑧! + 𝑠! !/!

!

!𝑑𝑠𝐳                      

𝑉 =𝛼4𝜀!

 𝑠!𝑧

𝑧! + 𝑠! !/!

!

!𝑑𝑠