tecnologías para educación · 2.slider's acceleration along the component of inclined...
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Tecnologías para Educación
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M1
M1
M1
M1
M1
M1
M1
M2
M2
M3
M3
M3
F01
F02
F08
F07
F11
F12
F13
F03
F14
F05
F15
F04
Mechanics of Machinery
Newton's Law Experiment
Projectile and Collision Experiment
Centripetal Force and Rotational Inertia
Compound Pendulum & Torsion Pendulum
Determine the Young's Module
Fundamental Fluid Experiment
Experiment of Venturi-Tube
Ripple Tank Experiment
Standing Waves and Resonance
Resonance Tube Experiment
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1
Topic Item No. Ti t le Objectives
Pendulum, Free Fall and Spring Harmonic Oscillation
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14
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21
22
23
H1
H2
O1
O2
O3
E1
E2
E3
E4
A1
A2
F16
F09
F10
F21
F20
F06
F17
F18
F19
F22
F23
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4
7
2
13
7
4
10
2
3
2
Topic Item No. Ti t le Objectives
Specific Heat, Equivalent of Heat and Thermal Expansion
The Measurement of Wavelength Spectrum on Grating Observation
Universal Law of Idea Gas
Geometrical Optics, and Interference
Polarization of Light
Microwave Optics
Fundamental Electricity and Electronics
Electric Field Mapping Apparatus
Magnetic and Electromagnetic Experiments
RC & RLC
Labware
Science Tables
Mechanics Heat Optics Electricity Atomic
Determine the Planck's Constant h by Laser
No. No.
W ith some fundamental principles
regarding mechanical work-energy
conservation proposed, Archimedes once
exaggeratedly said, "give me a place to
stand on with a lever, and I will move the
Earth". To further qualify physical
phenomena demonstrated above, our
experimental equipment including lever
arms and assembly pulley evaluating
effort-saving are established in this
subject. Of course, the spring coefficient
on Hooke's Law as well as static frictional
investigation is also examined. Thus the
identification of effort-saving might be
effectively implemented through the
performance of experimental devices
carried out in our mechanics package.
Objectives1.Static equilibrium forces combination, force decomposition.
2.Torque balance- parallel force of plummet, lever experiment on the different/same side, multiple torque, wheel & axle, the center of mass & gravity.3.Force of inclination-maximum static friction, coefficient of static friction, coefficient of dynamical friction and pulley system.4.Pulley- single/double sheave pulley, the comprehensive experiment of pulley.5.A variety of comprehensive experiments for practical application.6.Hooke's law.7.Single Pendulum.
Features1.The board formed by one-piece plastics makes experimental device more stable and easily mounted.2.Some parts have strong magnets on the back in order to avoid falling off during the experiment.
ExperimentStatic Equilibrium--- resultant forces at common pointAs the force equilibrium is reached, the resultant forces acted upon a point must be equal to be zero using the method of
parallel combination. Thus equation might be established.
The photograph of experimental device
Force combination in parallel method
Back adherence of strong magnets avoid the falling off part during
experimental operation.
The rigid materials are made out of one-piece plastics.
The force-length (cm)
01
0.074
0.321
1.84
1.770
3.9%
0.074
0.421
1.46
1.404
3.9%
0.094
0.421
1.79
1.757
2.0%
1 2 3
0.844
1.194
1.771
0.844
1.197
1.770
0.858
1.205
1.768
0.741
1.056
1.396
0.738
1.057
1.408
0.746
1.061
1.408
0.817
1.172
1.765
0.823
1.174
1.752
0.821
1.173
1.754
No.
m2 (kg)
m1(kg)
average 2av(m/s )
(%)
V0(m/s)
V(m/s)
experiment2a(m/s )
theory m2 g
m1 + m2
Objectives
1.With the aid of optical timers, slider's acceleration to verify Newton's
Second Law of Motion could be determined.
2.Slider's acceleration along the component of inclined plane, 'gsin '
is found to be dependent on the inclined angle, but irrelevant to
slider's mass.
3.Conservation of momentum in elastic and inelastic collisions.
4.Kinetic energy not conserved in inelastic collision.
Features
The self-designed slider on aluminum track not only provides a special
advantage in precision demand as well as easy-to-use characteristic,
it also could be extended to force vibration, damping analysis and
friction experiments if additional unit is involved.
Experiment---Acceleration Invoke fixed pulley system subjected to hanged weight, the slider,with velocity of V and Vo, travels through both optical timers in separated distances, its acceleration ,compared to theoretical value, could be formulated by
02
g2(s2t1 s1t2 )t1t2(t2 t1 )
s1 (cm)
s2 (cm)
t1 (s)
t2 (s)
1
0.07180
0.13056
946.9373
3.3
20
40
980
2
0.07174
0.13039
954.3902
2.6
3
0.07165
0.13046
934.2869
4.7
4
0.07187
0.13059
954.4257
2.6
IntroductionBy means of air resistance (also called drag), parachute helps the pilot
drift to the ground slowly and safely. That is attributed to the drag
counteracting free falling initiated by gravity acceleration. To meet this
purpose, a comprehensive experiment kit features several characteristic
are proposed: (1) experimental gravity acceleration might be figured out
using a photogate timer to measure the falling velocity of object at both
different heights. (2) According to the period recorded by photogate timer
and the length of pendulum, the experimental gravity acceleration can
also be determined.
Objectives1.The period of simple pendulum is measured by photogate timer in
order to study the phenomena of isochronism.
2.The velocity of free-falling object is measured by photogate timer, so
the user can estimate the acceleration of gravity.
3.The elastic coefficient of spring can be calculated on Hooke's Law.
Features1.Using magnetic adherence avoids operational error.
2.Adjusting the length of pendulum by double screws makes periodic
swing oscillation become more stable.
Experiment---Free fallWith a object freely falling through both vertical positions s1, s2 corresponding duration t1, t2 determined, gravity acceleration, in this experiment, might be estimated using a photogate timer
Iron ball, weight 63.6 g
error(%)
times
gravitational acceleration
g 2(cm/s )
experiment
theory
03
2.5
2
1.5
1
0.5
00 20 40 60 80
Hor
izon
Ran
ge x
(m)
Angle
Experiment
Theory
vb 2gRcm (1 cos )Mm
O1O
O2'
O1'
O'
1
P1i P2i P1f P2f
m1 v1i m1 v1f cos 1 m2 v2f cos 2
0 m1 v1f sin 1 m2 v2f sin 2
2
IntroductionThese experiment kits is designed to demonstrate the dynamic projected motion, which provides the user an useful manner to understand the conservation of mechanical energy. Here the transformation of potential/kinetic energy in elastic/inelastic collision will be clearly discussed. When the steel ball is jetted horizontally with three different velocities in various angles, the initial velocity can be predicted by the horizontal distance of a projected particle travels. Coupling with 2D or 3D of momentum conservation momentum conservation, the lost of kinetic energy will be converted to potential energy, and the initial velocity of a steel ball for ballistic pendulum might be computed under the consideration of perfectly elastic collision.
Objectives1.Kinematic equation of projectile motion can be formulated.2.Momentum conservation of a steel ball in elastic collision can be verified.3.With conservation of momentum and mechanical energy for perfectly elastic collision, the initial velocity of a ballistic pendulum in can be computed.
Experiment---Projectile motionWith adjustment of different angle and time, the horizontal distance of a projectile can be computed and compare to the measured value.According to equation: x xo (vocos )t y yo (vosin )t gt 2
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Experiment---Elastic collisionAs elastic collision between two balls is assumed, the momentum conservation will be satisfied during the collision process.According to the equation:
Experiment---Inelastic collisionWhen the mass m is released from initial height of Rcmcos , the impacted velocity of body M, after inelastic collision, might be
estimated base on formula given
h cm
R cmR cm
04
IntroductionAs our daily appliance, the rotational device could be found everywhere at anytime. Just like the rolling wheels in car's motion, gyroscope in the steamer, even the spinning skill in the athletic game, hurricane arisen from air of large vortex and the existence of spiral galaxy in universal space, they all are assessed from the dynamical characteristic of body rotation. In this subject, the experimental kit is designed to experience the characteristic of force responsible for rigid body in circular motion,and rotational inertia for rotating object induced by torque.
Objective
1. Centripetal force induced by various mass in different radius.2. Angular acceleration and moments of inertia of different bodies.3. Steiner's theorem (parallel-axis theorem).
Experiment--- Centripetal forceA body of mass M moves on a circular path, variable angular velocity might be produced by adjustable radius and rotating rate. The required centripetal force for the body, in terms of relative parameters, will be developed below.
Experiment---Moment of rotational inertiaBase on the Newton's second law F=ma and rotation motion for T=I , systematic moment of inertia could be summarized by individual moment of inertia, which depends on the separated mass and their distance to the rotating axis. I m ri i
2
Generalized from these experiments, a disk, mounted as the vertical shaft, is subjected to an external torque induced by a mass connected to a stretched string around pulley. Based on the value of hanged mass m, radius of disk R and angular acceleration, the rotational inertia of disk can be determined.
35
45
55
65
75
weights (g)
0.03484
0.04489
0.05478
0.06485
0.07483
repeat I repeat II repeat III
2Acceleration, a (m/s ) Mean a2(m/s )
2I' (g cm )
0.03491
0.04492
0.05490
0.06490
0.07486
0.03491
0.04491
0.05489
0.06491
0.07478
0.03489
0.04491
0.05486
0.06489
0.07482
mean
61230
61096
61066
60951
60926
61054 2Theoretical value 50977 g cm
2Experiment value [I'-I -I ]= 49802 g cm 0 theo
error=2.30%
Disc
05
O'
T
r
IntroductionBase on Newton's second law and energy conservation, we will forward torque and rotational theory to study harmonic motions in reversal compound pendulum and torsion pendulum, which have been widely used in practical application such as torsion or pendulum clocks, crank system of engine, mechanical pressure gage, damping device and rotary flow meter etc.
Objectives 1. compound pendulum the magnitude of gravity acceleration 2. torsion pendulum the stiffness coefficient of metal wire.
Experiment---Torsion pendulumA torsion pendulum, in Fig.a ~ Fig.b, is made up by a circular disk of mass M suspended at a copper wire of length L. Here the smaller periodic oscillation will be induced while the distortion of material's stiffness recovers from the torque subjected.
Experiment---Compound pendulumConsider a mechanism of compound pendulum as the sketch below. Here both nuts, taken as rotating pivot by turn, might be screwed on the pendulum, in which one is fixed and the other might be regulated. Thus both corresponding periodic profiles of T1 and T2 , resulted from the exchange of rotating shaft, could be accessed. While survey the equilibrant period T1=T2 as setting the moving nut at appropriate situation, the maximum value of + ( the addition of distance from mass center to individual rotating axis) coupling with corresponding period T will be used to precisely predict the magnitude of gravity acceleration. That is the working principle of so called" inverted pendulum (another style of compound pendulum) " proposed in this experiment.
Here I indicates disk- rotating moment of inertia and I , means the total 0 1
rotating moment of inertia if additional circular shell is co-axially positioned above. Base on the oscillating period of rotation T, material stiffness coefficient n might be determined.
06
Axis2T2
Axis1T1
Mass Center
F
H
L
IntroductionThe Young Modulus, named after Thomas Young (1773 to 1829) who was an outstanding British polymath in material fields, is usually used to define the proportionality of normal stress and normal strain for metal material subjected to external force. Such proportionality constant only prevails within the working region below elastic limit i.e., transient distortion or deflection of material might be recovered after the external force is removed. It is, of course, far lower than ultimate limit accessed where the permanent strain or failure of material will occur. Thus using the Young Modulus to predict the validity of substance, especially in elastic behavior, seems to be inevitable prior to it being in engineering application. Also it could be treated as an effective manner for engineer to evaluate the safety factor of substance selected for public construction.
Objectives1.Determine the Young' Module by metal wire2.Determine the Young' Module by deflection of a beam3.Determine the length and thickness by caliper gauge and micrometer
Experiment--- Determine the Young' Module by metal wireTo estimate the Young's Module of material, tension method and beam-deflection method are usually introduced using the instrument of load cell, vernier calipers and scalar meter. Firstly in tension method, the measurement of wire -enlargement ration L/L, caused by force F subjected to metal wire of one end fixed, might carried out, here radial displacement is assumed to be far smaller than the axial extension, i.e., only the shear stress and strain along the force component, in this subject, will be taken into account.
Experiment---Determine the Young' Module by Deflection of a BeamSecondly in beam-deflection method, the central deflection will be gradually augmented as the force F is enforced at. And Young's modulus based on the ration of bending stress and bending strain, might be yielded below while the state of material still falls within the elastic region.
F external force (N) L the elongation of bar (m)
L the length of bar (m) d the diameter of bar (m) L initial length of bar (m)0
2S cross section area of wire (m )
Steel wireF(N)
L (mm)0
L(mm)
L(mm)
D(mm)2Y(dyne/cm )
80.9
848
851.13
3.13
0.37
20.4
Y: Young ModulusH: central deflection of beamF: driving forceL: the length of beam between both supportsB: the width of beamt : the thickness of beam
F(N)
H(mm)
L(mm)
B(mm)
t(mm)2Y(dyne/cm )
27.5
8.36
139.56
22.97
0.75
23.1
Steel bar
07
F F
L0
Introductionit is generally designed as a venturi meter to measure the flow rate or
flow velocity, includes liquid or gas, inside the piping system of varying
cross-section. Base on the conservation of flow as well as mechanical
energy (Bernoulli equation), i.e. V(flow velocity) x A( cross-section area)
=constant and P (hydraulic static pressure)/ g + V2 /2g =constant, the
fluid flowing through pipe-throat will have the maximum local speed and
minimum hydraulic pressure which will induce the rise of water. While
refer to the elevation of liquid, the fluid velocity flowing along the center
line of piping system might be successfully.
Objectives1. Measure flow rate by timing the water collection.
2. Measure flow rate by flow meter of float-sink.
3. Measure flow rate by dynamical tube.
4. Measure flow rate by venturi tube.
Experiment ---Venturi TubeThe magnitude of static pressure, dynamical pressure as well as
estimated flow velocity might be easily accessed from the profile of liquid
elevated at each tube, which is mounted at different scale of diameter
along the pipe and used to confirm the validity of Bernoulli equation.
Coupling with volumetric flow continuity and Bernoulli equation in Eqs.(1)
~Eqs.(2), flow velocity traveling through venturi-pipe of variable diameters
will be developed in Eqs.(3).That also means local flow velocity might be
expressed in terms of liquid elevation indicating the static pressure
induced.
Here V is the local velocity flowing across the corresponding diameteri
D of pipe cross-aera A with liquid elevation h and Q means i i i
volumetric flow rate.
09
1
D D D D D D1 2 3 45 6
2 3 4 5 6
IntroductionWith the development of sound and hearing technology, such mechanical or digital device, widely applied in our daily lives, has attracted public interest and attention. By way of air medium, sound source, for example, conveying some specific frequency and amplitude could be easily detected by human ears, even the intensity is in lower state. In this subject, substance- wave behavior for ripple experience on the water pool is designed and experimented.
ObjectivesIn this subject, the water tank experiments are intended to produce different wave pattern depending on various geometry of actuator. Relevant ripple-experiment listed below will be surveyed.1.point wave2.straight wave 3.wave's reflection
Features1.The special designed product of aluminum and stainless behaves an easy-to-use characteristic, which makes the self-assemble accomplished, in five minutes, become possible.2.The primary LED irradiated source including white light, green light and blue light is enforced. Here Sine-wave signal source is used to configure free space wave-pattern, which could be also available in static and dynamical photo.3.By way of transparent projection board, ripple-profile might be promptly accessed with the paper drawing on above.4.Sparking frequency of irradiated source might be fitted while the photo is performed by IPHONE.
4.wave's refraction5.wave's diffraction6.wave's interference
7.reflection mirrors8.refractive lens9.Doppler effect
10
theory (cm) relative error (%)No. of wave node freq. f (Hz) experiment (cm)
average
Wavenumber n
closed pipe
open pipe
400
350
300
250
200
150
100
50
00 1 2 3 4 5 6 7 8
B C A E
N A N A N
/2
IntroductionTo survey the pipe-resonance of sound waves, a small amount of tiny Styrofoam balls is uniformly deposited in the transparent horizontal tube initially. And then related wave patterns of specific frequency, emitted from the loud-speaker, might be generated by regulating frequency-function generator. Just for sound resonance inside half open and half-closed pipe are concerned, an incident sound wave released from the speaker will be interfered by the traveling wave reflected from the end of pipe. As both identical but opposite-sign waves collide, the resonance of standing wave, through the superposition of wave packets, will be developed out if proper frequency is well-defined by function generator. Thus the resultant graphic profile could be easily visualized by the separated group of Styrofoam balls distributed inside the pipe. That will also lead the user to understand the characteristic of standing wave such as the accessed wavelength, fluctuated amplitude corresponding to individual resonance frequency.
preasure node preasure antinode
Standing antinode Standing node
Objectives1.As the resonance occurs in open or closed pipe, the experienced nodes and antinodes of standing waves might be determined from the experiment as well as theory.2.View from the ripple pattern, the crest and trough existing at sound wave profile will be characterized.3.Base on the measured wavelength, the traveling velocity of sound wave could be calculated.4.With the fallouts accessed from experiment, the discrepancy of resonance- formations for open and closed pipe will be investigated.
Experiment---Standing wave in closed pipeThis experiment is designed to investigate the standing waves in closed pipe. When the released sound wave is interfered with the wave reflected off the end of closed tube, the standing waves might occur due to the superposition of identical waves with opposite sign. By way of the envelope of Styrofoam balls, user can characterize its
formation and characteristic.
Wav
elen
gth(
cm)
Experimental values
Theoretical values
: pipe-lenghth
12
pV k
V bT
Pressure (kPa) Carnot cycle
Pulley 11mm (mm)2012 3 26 09:27:46-20 00 20 40 60 80 100 120 140 160 180
252015100500
b
ad
c
0 5000 10000 15000 20000 25000 30000 35000
50.045.040.035.030.025.020.015.010.0
5.00.0
Pressure (kPa) Boyle's law
3volume (mm )
2y=-0.001x+47.401 r =0.998
0 5000 10000 15000 20000 25000 30000 35000
80.070.060.050.040.030.020.010.00.0
Temperature ( ) Charle's law
3volume (mm )
40000
2y=0.002x+17.982 r =0.991
IntroductionTo survey fundamental thermodynamics, experiment kit of thermal engine, build-in-piston and gas cylinder, is developed to investigate the relationship among gas pressure, volume and temperature. Here the essential experiments including Boyle's law, Charles, Gay-Lussac's law, combined gas law, as well as Carnot cycle will be performed in this subject. Through thermal expansion or compression, work done accessed from heat engine cycle, operated in closed thermodynamic system, could be determined.
Objectives1.In this subject, ideal gas, used as a working medium, will be taken into account. Here the magnitude of pressure multiplied by volume will remains constant under the isothermal process. And a linear proportionality between volume occupied and thermal temperature will exist if iso-bar process is embarked. In addition, a linear relation for ideal gas pressure vs. thermal temperature is found to be followed for constant volume held.2.Examine the reversibility of Carnot Cycle.
Experiment---Carnot cycle The objective of this experiment is to establish a reversible gas power-cycle system. Here the work diagram, constituted by four p-v process, indicates a net work done/cycle (area bounded by the work diagram), and each might be estimated from the variation of gas pressure (p) with volume.
Experiment---Boyle s lawThrough isothermal expansion performed by thermal engine, gas pressure varying with volumetric expansion could be formulated by pressure sensor, which will be used to examine the suitability of Boyle's law. From the equation:
Experiment---Charles and Gay-Lussac's lawThrough isobar expansion achieved by thermal engine, the relation of gas volumetric expansion varying with working temperature could be determined by thermometer, which will be used to examine the suitability of Charles and Gay-Lussac's law.
'
14
Experiment---Colors mixing and propagation
y 2a a
L L
Experiment---The measurement of lens focus
Experiment---Single slit diffractionAs the light travels through a small size slit, it will diffract and spreads out to the both sides on the screen which is located at a specific distance from lens. After comparing theoretical and experimental value, the width ofcentral bright line and the spacing dark line might be yielded below.
y c d
y dy c
IntroductionAs we know, optics is very influential in everyday lives i.e., various colorful objects, from the moment we open our eyes in the morning, will be captured promptly. Maybe that is primarily attributed to different wavelengths of lights, reflected off objects, irradiated into eyes. Base on it, camera works might be carried out and developed. That means light rays from an object will pass through the lens of the camera and get recorded on a film. This experimental kit is designed to familiarize the user with the properties of geometrical optics and physical optics by observing light of different wavelength, reflection, refraction, interference, etc.
Objectives1.Propagation of light.2.Colors--Additive and subtractive mixing of colors.3.Mirrors--Determine the focal length of images on concave or convex mirror.4.Lenses--Determine the focal length of images on concave or convex lens.5.Prism--Deviation and invertion from refraction.6.Snell's Law--Determining the refractive index from rectangular lens or refraction tank.7.Wave optics--Compare the single slit, double slit and multiple slit, and determine the wave length of laser light source.
Features1.Easy to use measuring tape on the optical bench will be beneficent to the experimental performance.2.Magnetic accessories are designed for effective demonstration.3.Record data on the bench could be easily accessed by varying the position of displaying screen.4.Laser generator on the micro-scale adjustment will help effective demonstration.
15
IntroductionThe electromagnetic waves consisting of most common light source, such as Sun or laser ray might have its oscillation in different plane by turn as it travel toward specified direction (unpolarized light). Of course, we also might use a polarizer to change the mean distribution of light energy i.e., the intended component of incident ray (polarized light) will be allowed to pass through while the other components are left to be filtered.
ObjectivesMalus' Law of PolarizationBrewster's angle
Experiment---Law of MalusAs a completely plane polarized light is incident on the analyzer, the intensity I of light transmitted to analyzer is directly proportional to the square of cosine of angle between the transmission axes of the analyzer and polarizer.
Experiment---Brewster's angle
When an unpolarized light reflects off a nonconducting surface, it is partially polarized parallel to the plane of the reflective surface. There is a specific angle, , called Brewster's angle at which the 1
reflected ray and the refracted ray are 90 degrees apart and the light energy parallel to reflected plane will disappear.
As unpolarized light is sent at Brewster's angle into a series of glass sheets, electric field vector of refracted ray will become weaker due to the component perpendicular to incident plane might be partially disappear.
Inta
nsity
(mW
)
Angle(degree)
Reflected ray(polarised)
Refracted ray(slightly polarised)
unpolarized
p-polarized
s-polarized
incident ray(unpolarised)
16
IntroductionSimilar to light behavior, microwave, known as a style of electromagnetic wave, possess both volatile characteristic including wave propagation as well as matter particles. Here three fundamental wave propagations, such as micro-diffraction, reflection as well as absorption, have been acknowledged. To effectively undergo the intended experiment, the wavelength 3cm of frequency 10.5GHz, far greater than 400~700nm of visible light and 1.7cm of ultimate wavelength in sound wave, is selected. That not only features as a strong diffused manner to investigate the microstructure of substance, but the lower energy required also meets the demand of local experiment related to geometric and wave optics, acoustics, and electromagnetic communication.
Objectives1.Geometric optics reflection, refraction and standing wave.2.Interference diffraction, double-slit interference, Michelson interference, Fabry-Perot interference, Lloyd's mirror and Bragg's diffraction. 3.Polarization Brewster's angle, light polarized experiment. 4.Bragg diffraction 5.Fiber optics
Experiment---Bragg Diffraction
Experiment---polarization and Brewster's angle
Experiment---Michelson interference
Experiment---Double Slit Interference
(0 )(90 )
~56i
I
dsin dsin d
17
9876543210
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
0 0.2 0.4 0.6 0.8 1
VD(V)
180160140120100806040200
ID(m
A)
IntroductionJust for the twentieth century, the electricity, widely used for a variety of applications, has played a significant role in our daily life. In this experimental kit, students could learn how to constitute circuit loop without breadboard needed, which makes the experiment undertaken easily. In addition, teacher's demonstration on teaching board will become effective using test component enclosed by transparent block whose back is designed to be attached with magnet. Thus the user could instantly check the working state of electrical component inside the box and change it if necessary. This experiment is designed to familiarize the user with the concept of resistance, current, voltage, and basic properties of the transistor
Objectives1.Base on the measurement of voltage, current and resistance, Ohm's Law might be examined.2.Using Kirchhoff's Law to study current or voltage induced in multiple loop.3.Referred to Wheatstone bridges circuit- resistance is measured.4.Study the properties of diode and its working performance.5.Study the properties of PNP and its I-V characteristic curve.6.Study the gain value of PNP.7.Study PNP resistor's I-V curve.
Features1.Multiple experments regarding the electric circuit might be quickly constituted, which the breadboard is no longer needed inside selfdesigned box.2.Teaching demonstration on classroom board of magnetism-adherence will provide students an advantage in subgrouped experiment. 3.With the special design of experimental box made of transparent plastic, the diorder component might be replaced through the perspective view of circuit embeded.
Experiment---Ohm's LawAs the voltage V is subjected to both ends of a conductor, the current I, inversely proportional to the resistance R, will be induced. That meansV = IR
Experiment---the properties of diodes measurementThis experiment is designed to measure the current of diode under bias specified. A closed circuit will present if forward bias is enforced, and induced current will be cut off if the reverse bias is operated.
18
IntroductionBase on Coulomb's law, the magnitude of electric field E produced by single charge Q might be given below, which induce an irradiated outward electric field for + Q or irradiated inward direction of electric field for - Q. While consider the work done of charged particle moving in the electric field, the resultant potential difference might be formulated as below. Here the direction normal to measured equipotential lines, Vi =0,Indicate the intended electric field(as shown of dash line), in other words, the distributions of eletric field might be also concluded if the profile of equipotential lines is determined.
The designed device of smaller size, economical cost and easy-to-use offers a single conductor-bar shifting on the testing board of graphite,embedded in plastic plates with four popular patterns, permanently printed on in highly conductive paint to constitute the Wheatstone-bridge circuit, and then various equipotential lines, induced by different dipoles, might be easily outlined by individual contour with equal sub-potential accessed using single conductor-bar. In this subject, experimental knits will help us visualize the pattern of electric field (line of electrostatic force) which are orthogonal to the distributed equipotential lines measured from various aspects of electric dipoles.
Objectives1. Parallel plate capacitor
2. Two points within a field
3. Point and plane
4. The lighting rod
Experiment results
19
reference position
Measuring position
+A
+Q Q
N=15
Current(A) Angle( ) Baxis H
0.500
1.005
1.495
2.000
51.5
66.5
74.0
78.5
0.367491
0.403775
0.396103
0.375979
4.620E-05
9.286E-05
1.381E-04
1.848E-04
IntroductionIn1820, an electromagnetic theory was initiated by Oersted. Here the
physical experiment relative to magnetic field induced by a current-carry
wire was proposed. During 1820~1827, the theoretic model was further
quantified by Ampere's. In 1831, the so called Faraday's law amounted
the current induced along the closed loop while a time varying magnetic
flux, across the sectional area of coils, is undertaken. That also explains
the mutual relation between electric current and magnetic field, and has
become a fundamental principle for electromagnetic application in our
daily life. Base on quantity analysis from theoretic or empirical model,
the experimental kits, in this subject, also provides some interesting
demo related to electromagnetic demonstration.
Objectives1.Geomagnetic measurement :
Tangent Galvanometer
Determination by the magnetic moment
2.Magnetic effect of electric current and applications :
Current Balance DC Motor
3.Electromagnetic induction and applications :
Faraday's law Lenz's law
Self-inductance and mutual inductance
Generator Transformer
Magnetic communication
Experiment---Tangent Galvanometer With rotating angle of magnetic pin measured, axial magnetic field
induced from solenoid Baxis could be determined.
Experiment---Current BalanceApparent weight on the load cell,
experiment of Lorentz force,
could be induced by a current
carried by two parallel magnets.
Experiment---Faraday's lawIf a magnet is passed through a coil of conducting wire, a voltage
is induced (created) in the coil. The faster of the magnet moves
through the coil, the greater strength of voltage.
20
RLC circuit has a very important feature, that is, the produced amplitudes
of circuit-current will closely depend on the input frequency. Generally
speaking, partial signal will be filtered, but partial might be augmented as
several power sources with different frequency, in the circuit, are delivered
simultaneously. Here amplified signal of frequency is primarily determined
by the value of L and C selected. However the converse effect will appear
as the higher resistance R is involved. Thus the so called "filter effect"
might be taken as an important characteristic in RLC circuit. In addition,
RC circuit, in the absence of power supplier, is usually performed as a
convertor of electric energy in the envelope of electric field. Here the electric
energy charged into or discharged from capacitor C is based on the demand
of current flow in circuit. That might be also used as "Quick Battery" existing
in almost all electronic circuits.
Charge (discharge)circuit diagram
Objectives1. Investigate the time constant for value of C in charging or
discharging process of RC circuit.
2. Learn the resonant-frequency response for RLC in series
deployment.
Experiment---RC
In RC circuit, the voltage across capacitor is relative to the charge and
discharge time of capacitance. In fact, dimensionless-time value of R*C
we said it as a time constant for
circuit. By way of time varying
voltage profile accessed from
charging or discharging
process, the needed value of
capacitor might be determined.
Charge on capacitor vs. time duration
Discharge from capacitor vs. time duration
Experiment---RLC A fundamental RLC series circuit,
figured right, is primarily constituted
by electric resistor R, inductance
(L), capacitance (C) as well as AC
voltage. Specify a set of L,C in
circuit and a parallel voltmeter across the resistor R, a varying
voltage signal might be readable from voltmeter while adjust the
driving frequency of power source. As the regulated frequency is
close to natural oscillating frequency yielded below, signal resonance
will occurs in RLC circuit and the maximum voltage could be
displayed on the panel of voltmeter. Here the resonant frequency
accessed from the circuit-current and voltage signal across the
resistance. Referred to the so called "resonant frequency"
formulated above, corresponding response might be figured below,
and here the value of gain
of terminal voltage and
power supplied voltage,
might be estimated on
the profile sketched below.
Resonant response of voltage vs., time duration
will be also available to the fluctuated frequency
, defined as the ratio
n
Vs
R L C
21
h
IntroductionRather than the energy continuity considered in classic physics, the
energy level of a photon or an electron, viewed from quantum theory,
exhibits an integer multiple of hf (here h is planks constant and symbol
of f indicates the frequency of light wave). That means a light is emitted
from or absorbed by an electron and the energy, hf, will be quantized.
While laser light is irradiated to a light-emitting diode, the induced current
will be further retarded due to weaker forward voltage unable to overcome
the energy barrier, i.e., most electrons are still constrained in depletion
layer. However, a current of fast growth starts being induced if potential
supplied V is just adequate to break through the barrier. Thus planck's 0
constant h might be determined from the equivalence of energy emitted
from laser diode, hf, and power absorption of photon e ( V-V ). 0
Objectives1. Measure the Laser's wavelength by reflective diffraction or grid
diffraction.
2. Utilize the V-I characteristic of diode Laser to find the emitted voltage.
3. Determining Planck's constant.
Experiment---Laser wavelength by Reflective diffractionBase on the pattern of interference fringes reflected from the multi-
gratings on steel straightedge, the wavelength of laser might be
determined. Here the bright fringes occurs at
=dCos -dCos( + n )=n where f= vc/
Experiment---V-I characteristic of diode laserBase on V-I characteristic profile accessed from diode laser, an approximated equation following the linear behavior might be given. Here Vo, an interested point of linear equation and horizontal axis ( induced current), indicates the breakdown voltage of diode laser. And then the estimated planck's constant h, yielded below, is close to the result measured by Millikan (1916).
Reflecting Grating
diffracted light
Incident light
Linear Regression
Incident Grazing Angle (Rad)
100
x D
iffra
ctio
n A
ngle
(R
ad)
22
IntroductionIn general, light spectrum could be classified into discrete spectrum
and continuous spectrum. However, both absorption and emission are
the main typical pattern for discrete spectrum. Unlike the discrete way
mentioned above, typical continuous spectrum, in this experiment, will
be investigated. Here a slice with 500line / mm grate will be used to
observe the spectrum from incandescent lamps, sunlight and candles
(experimental mechanism as shown in Fig.1). While the below condition
is subjected, the wavelength of first order bright fringe (bright line
spectrum) emitted from mercury-containing fluorescent lamps and
LED lamps could be accessed as you view from the grating, whose
corresponding intensity will be displayed in Fig.2. Symbols d, l, s
individually designate the grating spacing, half width of first order bright
line and the distance from light source to grating.
Fig.2 The plot of intensity for bright fringe
Objectives1.Observation of continuous spectrum from incandescent lamp2.Determination the wavelength of emission spectrum from fluorescent lamp
Experiment---Wavelength spectrum of mercury-containing fluorescent
Fig.1 Diffraction of grating light with wavelength
Lightsource
screen
eye
S
2
Red
Yello
w
Gre
en
Aqua
mar
ine
Pur
ple
Deep
Pur
ple
Red
1 2
3
4
56
78
70286908
6714
62346124
60735791
5770
5461
49644916 4358 4078
( )4047
1 2 33 2 1 m=0(b)
0(a)
m=0
Intensity
1 2 33 2 1
23
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CIENYTEC LTDA
www.cienytec.comTecnologías para Educación