Midterm10 solution

Midterm10 solution - of the four corners of a square, as...

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

View Full Document Right Arrow Icon
PHYSICS 142B – Virtual Midterm Exam Solutions 1. Two charged objects are 4.00 m apart. One object has a mass M 1 = 2.00 mg and charge Q 1 = 3.00 μC, while the other object has a mass of M 2 = 5.00 mg and a charge of Q 2 = 2.00 μC. Both particles are simultaneously released from rest. Calculate the speed of the object with mass 2.00 mg after a very long time. Use conservation of energy and momentum as there will be two unknowns 2. A conducting spherical shell with inner radius a and outer radius b has a positive point charge Q at its centre as shown in the diagram below. The total charge on the conducting shell is – 3Q. Derive expressions for the E-field in terms of the distance r from the centre for the regions: r < a, a < r < b and r > b. a b Q Conducting shell (-3Q)
Background image of page 1

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

View Full DocumentRight Arrow Icon
3. Three long parallel wires are perpendicular to the plane of the drawing and pass through three
Background image of page 2
Background image of page 3

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

View Full DocumentRight Arrow Icon
Background image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: of the four corners of a square, as shown in the diagram below. The side of the square is 2.010306 cm. The two wires through the opposite corners have identical currents, I 1 = I 2 = 6.00 A. (a) What should be the current in the third wire so that the B-field at the fourth (empty) corner is zero? (b) What is the direction of the magnetic force on the third wire? I 3 = ? I 1 (into page) I 2 (into page) 4. Consider the circuit shown. (a) The capacitor is fully charged. (i) Calculate the currents in all resistors. (ii) What is the charge on the capacitor? switch 50 F 10 30 9 V 20 40 (b) After fully charging the capacitor, the switch S is now opened. After how long from the moment the switch is opened will the charge on the capacitor be equal to of its initial value?...
View Full Document

This note was uploaded on 10/14/2010 for the course EE PHYS 142 taught by Professor Re during the Winter '09 term at McGill.

Page1 / 4

Midterm10 solution - of the four corners of a square, as...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online