Exam2_2003Spring_Solutions

# Exam2_2003Spring_Solutions - Physics 8.02 Exam Two Mashup...

This preview shows pages 1–4. Sign up to view the full content.

Physics 8.02 Exam Two Mashup Solutions Spring 2003 Some (possibly useful) Relations: F = 1 4 πε o q 1 q 2 r 2 E = q 4 o r 2 ˆ r observer to source from points r ˆ = surface closed o inside Q ε dA E outside to inside from points dA = = b a a b b to a from moving V V V ds E 0 = ds E V point charge = q 4 o r = = N i i o i q V 1 4 r r charges point many V Q C = C Q V = U = 1 2 C V 2 = Q 2 2C I = qn A wire v drift drift wire I qn A == Jv where is the resistivity ρ = EJ 1/ where the conductivity σ σρ = JE V = i R L L R A A 1 R parallel = 1 R 1 + 1 R 2 R series = R 1 + R 2 R V R i V i P heating ohmic 2 2 = = = (joules/sec) 2 ˆ 4 o q r µ π × = vr B 2 ˆ 4 o I r × = ds r dB Ampere’s Law: through o contour I = ds B where I through is the current flowing through the open surface bounded by the contour = surface open through I dA J ds right-handed wrt dA F = q v × B ext ext I = × dF ds B Circumferences, Areas, Volumes: 1) The area of a circle of radius r is r 2 Its circumference is 2 r 2) The area of a sphere of radius r is 4 r 2 . Its volume is 3 3 4/ r The area of the sides of a cylinder of radius r and height h is 2 rh Circular motion: For a particle of mass m to move in a circle of radius R at speed v , there must be an inward force of

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
NAME______________________ page 2 magnitude R mv 2
8.02 2 nd Exam Name_____________________ Spring 2003 Solutions Page 3 Problem 1 (25 Points) Circle your choice for the correct answer to the six questions below. A: A current I is uniformly distributed over the cross-section of a conducting wire of radius a . For distances r from the center of the wire with r < a , 1. The magnitude of the magnetic field does not depend on r . 2. The magnitude of the magnetic field is proportional to 1/r 3. The magnitude of the magnetic field is proportional to r 4. The magnitude of the magnetic field is proportional to 1/r 2 5. The magnitude of the magnetic field is proportional to r 2 B: A segment of a wire of length dl carries a current I (see sketch below). The magnitude of the magnetic field due to this wire segment at the location P shown in the sketch is 1. [] 2 / 3 2 2 4 b a dl a I o + π µ 2.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 11

Exam2_2003Spring_Solutions - Physics 8.02 Exam Two Mashup...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online