Log in
Physics
1
answer
0
watching
61
views

If you were to cut a small permanent bar magnet in half,
a. each piece would in itself be a smaller bar magnet with both north and south poles
b. neither piece would be magnetic
c. one piece would be a magnetic north pole and the othe piece would be a south pole
d. none of these are true

Watch
1
answer
0
watching
61
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Rochelle Enrera
Rochelle EnreraLv10
9 Apr 2021

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share

Related textbook solutions

Physics: Principles with Applications
7th Edition, 2013
Giancoli
ISBN: 9780321625922

Related questions

1a) Faraday discovered that a current is induced in a coil

A) only when the N pole of a magnet is inside the coil
B) only when the S pole of a magnet is inside the coil
C) only when there is a magnetic field inside the coil
D) only when the magnetic field inside the coil is changing

1b). A conductor moves through a uniform magnetic field at speed v and has a motional emf V created across it. If the conductor were to move twice as fast through the magnetic field, the motional emf would be:

A) V
B) 2V
C) 4V
D) V/2
E) V/4

1c) In the conducting rail discussed in section 25.2 (where the rail is moving at constant speed), what can you say about the power input due to the person pulling on the rail and the power dissipated in the resistance?

A) Power input from pull = power dissipated in R
B) Power input from pull > power dissipated in R
C) Power input from pull < power dissipated in R

1d) The electric generator as shown in the reading generates electricity by:

A) rotating a loop inside a magnetic field
B) moving a magnet in and out of a loop
C) sliding a loop over a magnet
D) running current through a loop in a magnetic field

1e) The magnetic flux through a loop:

A) is proportional to the number of magnetic field lines going through it
B) depends just on the B field going through the loop
C) is maximized when the B field lines in the plane of the loop
D) is zero when the B field is perpendicular to the plane of the loop
E) doesn't depend on the direction of the B field

1f) According to Lenz's Law, the induced B field (due to the induced current) will:

A) be in the opposite direction of the existing B field
B) be in the same direction as the existing B field
C) be in the same direction as the change in the existing B field
D) be in the opposite direction of the change in the existing B field

1g) A stationary coil experiences a doubling of its magnetic field (no change in direction of the field) in a time T and has a given induced EMF. If the same change were to have happened in half the time (T/2), the induced EMF would have been:

A) half as large
B) the same
C) twice as large
D) one-fourth as large
E) four times as large

1h) Eddy currents:

A) make it hard to pull a nonmagnetic material through a magnetic field
B) make it hard to pull a magnetic material through a magnetic field
C) speed up a magnetic material moving through a magnetic field
D) speed up a nonmagnetic material moving through a magnetic field

 

 

We are doing an experiment in my physics lab that involves trying to find the horizontal component of the Earth's magnetic field. Here is a little explanation of what is going on: We have a bar magnet that is placed inbetween a set of Helmholtz coils (125 of them coiled) and we place a certain current (i) on the coils. We then see that the bar magnet begins to try to align itself with the magnetic field, but it will have an angular momentum that will cause it to continue turning past the direction of the magnetic field creating oscillations. Our instructor told us to count 25 oscillations and find the time it takes for 25 to occur. From that we can then find the period of oscillations(T) from each current. Then we can find 1/T^2 from this. We then plot a graph with current(i) on the x-axis and 1/T^2 on the y axis and we find its a straight linear line. Our Instructor stated that the y-intercept will be our b and our slope will be S. From the equation given in our packet which is: (32pN x 10^-7/r x radical 125) x b/S. I know that N is the number of coils, r is the radius(9.6cm), b is the y-intercept, and S is the slope. However, from my graph, my equation for the line of best fit was y=0.967x - 0.3068. plugging this in (32p(125) x 10^-7/9.6cmx radical 125) x (.3068/.967) I get 4.643x10^-4. Putting this into gauss by multiplying times (10^4) i get 4.64 which i know is far off since NASA says its around 0.2-0.5 gauss average around Earth. I would really appreciate the help for what im doing wrong.

chapter 32 problem 53

Suppose that the magnetic dipole moment of Earth is 7.0x1020 J/T. (a) If theorigin of thismagnetism were a magnetized iron sphere at thecenter of Earth, whatwould be itsradius? (b) What fraction of thevolumeof Earth would such a sphere occupy? The radius of Earth is6.37 x106 m. Assume complete alignment of thedipoles.The density of Earth's inner core is 11 g/cm3.Themagnetic dipole moment of an iron atom is 2.1 x10-23J/T. Iron has a molar mass of 55.9 g/mol.(Note: Earth's inner coreis in fact thought to be in both liquidand solid forms and partlyiron, but a permanent magnet as thesource of Earth's magnetism hasbeen ruled out by severalconsiderations. For one, the temperatureis certainly above theCurie point.)

(a) Number Unitsm

(b)


Thank you

Weekly leaderboard

Home
Homework Help 3,900,000
Physics 110,000
Start filling in the gaps now
Log in