Download D - TSG@MIT Physics

D.
ELECTROSTATICS
Electric Charge
D1
Amber and Glass Rods with Tinsel: An amber rod rubbed with fur is
repels the latter. The positively-charged fur, however,
attracts the tinsel. A
glass rod rubbed with silk is charged positively and also
attracts
the
tinsel.
Touching the tinsel discharges it. The demonstration can
be
repeated
starting with the glass rod. Ref: hb x1
D2
Amber and Glass Rods with He-Filled Balloons: A negativelyrepelled by the rod. A positively-charged glass rod attracts the
balloon.
The
same sequence is repeated with an uncharged, non-conducting
balloon.
This time, the balloon sticks to the amber rod after touching it.
Ref: hb x2; wl tape 1-01:00:23
charge
D3
Amber Rod and Comb with He-Filled Balloon: A conducting
attracts the balloon.
balloon
D4
Demonstration of an Electroscope: An electroscope is projected on
plane to protect the electroscope leaf from breaking.
Ref: hb x3
D5
Two Charged Conducting Ping-Pong Balls on a Stand: Two
and stay at an angle to the vertical. This can be shadowprojected on the
wall or TV-projected on the video screen.
Ref: hb x4
D.
D6
Static Charging by Rug Scuffing: The demonstrator scuffs his feet
Ref: wl tape 2-02:34:16
D7
Confetti and Van de Graaff Generator: Confetti placed atop a Van de
Ref: hb x8; wl tape1-01:05:13
conduc
on
ELECTROSTATICS (Cont.)
Electric Charge
D8
from his head.
Charged Person using Van de Graaff Generator: The lecturer
stands
Ref: wl tape 1-01:07:55
D9
Coulomb's Law using Charged Pith Balls: Two pith balls within a
wall to note the distance between the balls. The pith
balls are brought into
contact with each other and charged. They acquire
equal charge and repel
each other. As the position of the movable pith
ball is changed, the amount of
repulsion of the suspended one varies.
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d1
D10
Coulomb's Law using a Current Balance: A conducting plate
deflect from its initial position. Weights are then added to bring the
top plate
back to its initial position and determine the force of repulsion
between
the
plates. A helium-neon laser beam reflected off a mirror on the
top
plate
is
projected on the wall showing that plate's initial position.
balance
D11
Electrically Charged Student: A student sits on an insulated stool.
tinsel). They then discharge through a neon tube which
flashes brightly.
Ref: hb x5; wl tape 1-01:02:03
Electrostatic Induction
D12
Amber Rod and Electroscope: A negatively-charged amber rod is
the knob of the electroscope leaves a net positive charge on it. This can
shown by approaching the electroscope with the negative amber rod.
This
demonstration can also be done with a Braun Electroscope.
Ref: hb x3
D13
D.
be
Demonstration of the Electrophorus: The electrophorus consists of a
ELECTROSTATICS (Cont.)
Electrostatic Induction
D13
Demonstration of the Electrophorus (Cont.): The metal disk is
Ref: hb x12
placed
D14
Demonstration of the Wimshurst Machine: A Wimshurst electrodistance between the electrodes, higher potential differences
can be built up.
Larger charges can be stored by connecting the knobs to
Leyden
jars
which are component parts of the machine.
Ref: hb x23
D15
Two Identical Spheres Charged by Induction: The electrophorus
in the two small spheres. When separated,
they keep their induced charge. This
can be demonstrated with an
electroscope. This demonstration can also be
done with two 4'' balls on
insulated stands and an amber rod.
Ref: wl tape 1-01:24:00
Electric Fields
D16
Electric Field Lines: A sealed transparent acrylic container filled with
special piezoelectric pistol with an output of 5 kV is used to charge the
1) parallel plate capacitator
2) a circle and a point
3) a pattern of two concentric circles that demonstrates electrostatic
4) two like-charge points
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d2
5) two unlike-charge points
D17
Bouncing Balloon between Demonstrator and Van de Graaff
distance, the balloon will follow the electric field lines.
Ref: hb x10; wl tape 1-01:15:43
D.
ELECTROSTATICS (Cont.)
Electric Fields (Cont.)
D18
Conducting Ping-Pong Ball between Capacitor Plates: A conductthe Wimshurst machine, the ball follows the fringing electric field lines
between
the outer surfaces of the plates. The ball can also be placed
between
the
plates, in which case it bounces repeatedly between the plates.
Ref: hb x24; wl tape 1-01:29:00
D19
Electric Chimes: Two electrically-connected metal chimes are mounted
when the latter are connected to the electrodes of the
Wimshurst machine or
when the whole apparatus is placed atop a VdG
generator.
D20
Conducting Ping-Pong Ball between Two Spheres: A conducting
ball transfers charge from one sphere to the other as it bounces between the
two and eventually comes to rest when the potentials are nearly
equalized.
Removing the rod away from the sphere restarts the oscillatin
until the spheres
have once more no charge on them.
Ref: hb x11
D21
Fields of a Sphere and an Infinite Plane: A large vertical conductmakes an angle with the vertical. As the pith ball is moved away
from the
plane, the angle of the string remains essentially the same. The
same
process is then repeated with a VdG sphere as the electric field
source.
This
time, the angle of the string decreases with distance from the
sphere.
This
demonstration can also be done with a conducting He-filled
balloon and the
large VdG generator.
Ref: wl tape 1-01:18:42
D22
Dipole in a Van de Graaff Generator Field: A dipole consisting of
dipole is held in the field of a VdG generator. Going around the VdG, the
sensitive.
Ref: hb x9; wl tape 1-01:10:01
D.
ELECTROSTATICS (Cont.)
Electric Fields (Cont.)
D23
Dipole between Capacitor Plates: A small dipole on a rotating stand
of the capacitor. The potential on the plates can be reversed
with a switch
and, each time, the dipole realigns itself with the new field.
D24
Fluorescent and Neon Tubes in a Van de Graaff Generator Field:
away from the VdG. The same can be done with a small
neon tube. Also, the
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d3
Genera
tubes can be hand-held and made to flash by grounddemonstration is done only with the large VdG.
Ref: hb x19; wl tape 1-01:32:14
ing.
This
D25
Bucket in a Van de Graaff Generator Field: A bucket on an insulatNext, charge is taken from the opposite side of the bucket and
transferred
to
the same electroscope. The electroscope discharges showing
the
opposite
sign of the induced harges on each side of the bucket.
Ref: wl tape1-01:36:23
D26
Electric Field inside a Hollow Conductor: (By Induction) A
inside the container. Because of the absence of an
electric field inside the
container, the spheres get no charge. If the same
process is repeated outside
the container, the spheres become charged
oppositely. This is shown with
an electroscope. This demonstration can
also be done with a hollow sphere
Ref: hb x13, x15; wl tapes 1-01:24:00 & 01:36:23
conduc
D27
Location of Charge on an Insulated Hollow Conductor: A hollow
sphere and transfer it to an electroscope, but no charge is
picked up. The
same process is repeated on the outer surface of the sphere.
This
time,
charge is found to reside there. This demon- stration can also be
done with
a bucket.
Ref: hb x13, x15; wl tape 1-01:36:23
D.
ELECTROSTATICS (Cont.)
Electrostatic Potential
D28
Surface Distribution of Charge: A tear drop-shaped conductor on an
demonstrated that the charge density is greater at the areas of
greater
curvature. This demonstration can also be done with a bucket.
Ref: hb x20; wl tape 1-01:46:26
D29
Breakdown of Air (Lightning & Corona Discharge): Different
between the VdG and the spheres. Smaller spheres
result in longer sparks.
A sharp point at the end of the discharge rod
produces a Corona discharge
(St. Elmo's fire). A shadow-projected
electroscope placed nearby shows
that discharge is actually taking place.
Ref: hb x18, x21; wl tape 1-01:48:40
D30
Discharge of a Conductor by Surrounding Ions: An electroscope
Ref: wl tape 2-02:30:20
D31
Electrostatic Pinwheel: A conducting pinwheel is made of a horizontal
same polarity of these ions and the points, the latter are repelled and the
pinwheel rotates.
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d4
sized s
Electrostatic Shielding (D32,D33)
D32
Faraday's Cage: The lecturer stands inside a large screen cage and is
cage remains unaffected.
Ref: hb x22, wl tape 1-01:42:23
D33
D.
Cylindrical Wire Mesh Cage: Tinsel or an uncharged electroscope
ELECTROSTATICS (Cont.)
Electrostatic Potential (Cont.)
D34
Principle of the Van de Graaff Generator: Charge from a 5 kV
bucket is measured by an E-field probe and the Keithley
Electrometer.
Eventually, the amount of charge on the bucket reaches a
plateau. Charge
is then repeatedly transferred to the inside of the bucket.
This
time
a
much higher potential is achieved.
Ref: hb x17; wl tape 2-02:23:11
D35
Kelvin Water Drop Generator: This electrostatic generator consists
10 kV before discharging across a spark gap. The electrodes and sparks
Ref: hb x34; wl tapes 2-02:43:00 & 3-03:04:11
D36
Spare
D37
the
8/96
power
of
Smoke Precipitator: A rectangular tranparent container is filled with
smoke and illuminated so as to make the smoke visible. A high-voltage
terminal in the container is connected to the Wimshurst machine. When
Wimshurst is cranked, the smoke swirls and is quickly dissipated.
d5