When a bar magnet is suspended freely its north pole always point to O a. geographic south O b. geographic north O c. magnetic north of earth d. geographic east

23. A 1000-kg car moves west along the equa- tor. At this location Earth's magnetic field is 3.5 × 10-5T and points north parallel to Earth's surface. If the car carries a charge of −2.0 × 10¯³ C, how fast must it move so that -3 the magnetic force balances 0.010% of Earth's gravitational force exerted on the car?

A power line carries a current of 97 A west along the tops of 8.5-m high poles. 1) How does this compare with the Earth's magnetic field of about 1212 G? 2) Where would the wire's magnetic field cancel the Earth's field?

An unknown particle (m=1.23x10¯20kg) with 5 electrons in deficit enters a region between two parallel plates (V = 89132.5V) at a speed of 3.45x10®m/s. After exiting from between the plates, it enters into a region with a perpendicular magnetic field (Bext = 10.98MT into the page) V=89132.5V X X Pest.= 10.98 mT M= 1.23 X10 V; - 3.45, r= _ = ? _cm **NOTE: Complete ALL three (3) parts of this written question (#23, 24 & 25) on ONE separate piece of paper then take a photo and insert the ONE image in the "Your Answer" section of Question #23. The "Your Answer" sections for Questions 24 & 25 can be left blank. Thanks! :) X x X X X X X x X X

10) The magnetic field strength at the north pole of a 2.0 cm diameter, 8 cm long Alnico magnet is 0.10 T. To produce the same field with a solenoid of the same size, carrying a current of 1.5 A, how many turns of wire would you need? A) 5200 B) 4200 C) 2200 D) 3200

14. In Oersted's experiment, suppose that the compass was 0.15 m from the current-carrying wire. If a magnetic field of one-third the Earth's magnetic field of 5.0 x 105 T was required to give a noticeable deflection of the compass needle, what current must the wire have carried? Chap 22_#49

29. You can change the magnetic flux through a given surface by a. changing the magnetic field. b. changing the surface area over which the magnetic field is distributed. c. changing the angle between the magnetic field and surface in question. d. e. any combination of a through c. none of these strategies.

At a particular instant, an electron moves eastward at speed V in a uniform magnetic field that is directed straight downward. The magnetic force that acts on it is_____ A zero.   B. directed upward   C. directed to the south   D. directed to the north.

8. A wire carrying a 36.0–A current passes between the poles of a strong magnet that is perpendicular to its field and experiences a 2.15–N force on the 4.40 cm of wire in the field. What is the average field strength?   This is not and will not be graded

3. A proton moving eastward with a velocity of 5.0 km/s enters a magnetic field of 0.20 T pointing northward. What are the magnitude and direction of the force that the magnetic field exerts on the proton? (qe=+1.60 × 10-19 C)