Electricity and Magnetism Answers

A sphere of homogenous linear dielectric material is placed in an otherwise uniform elctric fild E not . find the elctric field inside the sphere?

You go to the power station. You need from the power station to your house. The station has primary windings of 10 and secondary windings of 10,000. If your house has primary winding of 10,000 and the total voltage needed is 240 V, how much would you need from your house?

When a glass rod is rubbed with silk, the rod becomes positively charged, but when a rubber rod is rubbed with fur, the rubber becomes negatively charged. Suppose you have a charged object but don’t know whether its charge is positive or negative. Explain how you could use a glass rod and piece of silk to determine the sign of the unknown charge on the object.

For a long, straight, current-carrying conductor, use Ampere’s law to find the magnitude

and direction of its magnetic field. Assume it’s radius is negligible.

A particle of mass m and charge q > 0 is at the origin at t = 0 and moving upward with velocity V~ = V yˆ.
Its subsequent trajectory is shown in the sketch. The magnitude of the velocity V =
V~
is always the same,

although the direction of V~ changes in time.



(a) (1 point) For y > 0, this positive charge is moving in a constant magnetic field which is either into the
page or out of the page. Is that magnetic field for y > 0 into or out of the page?
(b) (3 points) Derive an expression for the magnitude of the magnetic field for y > 0 in terms of q, m, R
and V .
(c) (3 points) For y < 0, the charge is moving in a different constant magnetic field. Is that field for y < 0
into or out of the page? What is the magnitude of that magnetic field in terms of q, m, R and V ?
(d) (3 points) How long does it take the charge to move from the origin to point P (see sketch) along the
x-axis. Give your answer in terms of R and V

Two singly ionized atoms move out of a slit at point S, as shown in figure, and into a magnetic
field of magnitude 0.100 T pointing into the page. Each has a speed of 1.00 × 106 m s−1

. The nucleus of the
first atom contains one proton and has a mass of 1.67 × 10−27 kg, whereas the nucleus of the second atom
contains a proton and a neutron and has a mass of 3.34 × 10−27 kg. Find their distance of separation when
they strike a photographic plate at P.

Two singly ionized atoms move out of a slit at point S, as shown in figure, and into a magnetic
field of magnitude 0.100 T pointing into the page. Each has a speed of 1.00 × 106 m s−1
. The nucleus of the
first atom contains one proton and has a mass of 1.67 × 10−27 kg, whereas the nucleus of the second atom
contains a proton and a neutron and has a mass of 3.34 × 10−27 kg. Find their distance of separation when
they strike a photographic plate at P.

A particle of mass m and charge q > 0 is at the origin at t = 0 and moving upward with velocity V~ = V yˆ.
Its subsequent trajectory is shown in the sketch. The magnitude of the velocity V =



Mod V~


 is always the same,
although the direction of V~ changes in time.

(a) For y > 0, this positive charge is moving in a constant magnetic field which is either into the
page or out of the page. Is that magnetic field for y > 0 into or out of the page?
(b)Derive an expression for the magnitude of the magnetic field for y > 0 in terms of q, m, R
and V .
(c)For y < 0, the charge is moving in a different constant magnetic field. Is that field for y < 0
into or out of the page? What is the magnitude of that magnetic field in terms of q, m, R and V ?
(d) How long does it take the charge to move from the origin to point P (see sketch) along the
x-axis. Give your answer in terms of R and V .

A magnetic field does not exert a force on a what?

Two coils, held in fixed positions, have a mutual inductance of 100 μH. What is the peak voltage in one when a sinusoidal current given by I (t) = (10.0 A) sin
(1 000t) is in the other coil?