SF Physics Experiments

SF

SCIENTIFIC www.sfscientific.com

Mechanics Heat Electricity Optics Atomic Labware Tables

SF Scientific---

SF Scientific Co., Ltd. is a design and manufacture company in Taiwan. We specialize in developing, manufacturing, and distributing physics experiment equipment for high schools.

We have supported students in honors class and science class with their international physics competition in Taiwan, and also engaged in international bids for high school science experiment equipment in a few countries. Now, we are pleased to show you an economic and complete set of 23 experiment equipment for high school teachers. The equipment will help teachers demonstrate and students learn through experiments such as mechanic, optics, thermodynamics, electricity, and modern physics.

No. Topic Item No.

Objectives

Ti t l e

No. Topic Item No.

Objectives

Ti t l e

1

M1

F01 Mechanics of Machinery

7

13

H1

Specific Heat, Equivalent of Heat and F16 Thermal Expansion

3

2

M1

F02 Newton's Law Experiment

4

14

H2

F09 Universal Law of Idea Gas

4

3

M1

F08

3

15

O1

F10 Geometrical Optics, and Interference

7

4

M1

F07 Projectile and Collision Experiment

3

16

O2

F21 Polarization of Light

2

5

M1

F11 Centripetal Force and Rotational Inertia

3

17

O3

F20 Microwave Optics

13

6

M1

F12 Compound Pendulum & Torsion Pendulum

2

18

E1

F06 Fundamental Electricity and Electronics

7

7

M1

F13 Determine the Young's Module

3

19

E2

F17 Electric Field Mapping Apparatus

4

8

M2

F03 Fundamental Fluid Experiment

13

20

E3

F18 Magnetic and Electromagnetic Experiments 10

9

M2

F14 Experiment of Venturi-Tube

4

21

E4

F19 RC & RLC

2

10

M3

F05 Ripple Tank Experiment

8

22

A1

F22 Determine the Planck's Constant h by Laser

3

11

M3

F15 Standing Waves and Resonance

5

23

A2

F23

12

M3

F04 Resonance Tube Experiment

1

Pendulum, Free Fall and Spring Harmonic Oscillation

The Measurement of Wavelength Spectrum on Grating Observation Labware Science Tables

Mechanics

Heat

Optics

Electricity

Atomic

2

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.

Objectives 1.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.

Experiment Static Equilibrium--- resultant forces at common point As 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.

Features 1.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.

The photograph of experimental device

Force combination in parallel method

The force-length (cm)

Back adherence of strong magnets avoid the falling off part during experimental operation.

The rigid materials are made out of one-piece plastics.

01

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 '

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

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.

No.

1

2

3

m2 (kg)

0.074

0.074

0.094

m1(kg)

0.321

0.421

0.421

theory m2 g m1 + m2

1.84

1.46

1.79

V0(m/s)

0.844 0.844 0.858 0.741 0.738 0.746 0.817 0.823 0.821

V(m/s)

1.194 1.197 1.205 1.056 1.057 1.061 1.172 1.174 1.173

experiment a(m/s2) 1.771 1.770 1.768 1.396 1.408 1.408 1.765 1.752 1.754 average 1.770 1.404 1.757 av(m/s2) (%)

3.9%

3.9%

2.0%

02

Introduction

Experiment---Free fall

By means of air resistance (also called drag), parachute helps the pilot

With 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

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

g

2(s2t1 s1t2 ) t1t2(t2 t1 )

Iron ball, weight

63.6

g

different heights. (2) According to the period recorded by photogate timer and the length of pendulum, the experimental gravity acceleration can also be determined.

times

1.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

2

s1 (cm)

20

s2 (cm)

40

t1 (s)

Objectives

1

0.07180

0.07174

3

4

0.07165

0.07187

t2 (s) 0.13059 0.13056 0.13039 0.13046 gravitational experiment 946.9373 954.3902 934.2869 954.4257 acceleration theory 980 g(cm/s2) error(%) 2.6 3.3 2.6 4.7

the user can estimate the acceleration of gravity.

3.The elastic coefficient of spring can be calculated on Hooke's Law.

Features 1.Using magnetic adherence avoids operational error.

2.Adjusting the length of pendulum by double screws makes periodic swing oscillation become more stable.

03

Introduction

Experiment---Elastic collision

These 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.

As elastic collision between two balls is assumed, the momentum conservation will be satisfied during the collision process.

According to the equation: P1i P2i P1f P2f

m1 v1i m1 v1f cos 0 m1 v1f sin

1 1

m2 v2f cos m2 v2f sin 2

2

O2'

O

2

O1

Objectives

O'

1

1.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 motion With adjustment of different angle and time, the horizontal distance of a projectile can be computed and compare to the measured value.

1 2 According to equation: x xo (vocos )t y yo (vosin )t 2 gt

O1'

Experiment---Inelastic collision When 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

vb

M m 2gRcm (1

cos

)

Horizon Range x(m)

2.5 2

R cm

1.5

R cm

Experiment Theory

1

0.5

hcm

0 0

20

40

60

80

Angle

04

Introduction

Experiment---Moment of rotational inertia

As 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.

Base 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 i ri 2

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).

Generalized from these experiments, O' 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 r the value of hanged mass m, radius of disk R and angular acceleration, the rotational inertia of disk can be determined.

T

Disc

Experiment--- Centripetal force A 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.

Acceleration, a (m/s2) repeat I

repeat II

repeat III

Mean a (m/s2)

35

0.03484

0.03491

0.03491

0.03489

61230

45

0.04489

0.04492

0.04491

0.04491

61096

55

0.05478

0.05490

0.05489

0.05486

61066

65

0.06485

0.06490

0.06491

0.06489

60951

75

0.07483

0.07486

0.07478

0.07482 mean

60926

weights (g)

Theoretical value 50977 g cm

I' (g cm 2)

61054

2

Experiment value [I'-I 0-I theo]= 49802 g cm2 error=2.30%

05

Introduction

Experiment---Compound pendulum

Base 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.

Consider 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.

Objectives 1. compound pendulum the magnitude of gravity acceleration 2. torsion pendulum the stiffness coefficient of metal wire.

Experiment---Torsion pendulum A 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.

Mass Center

Axis1 T1

Axis2 T2

Here I0 indicates disk- rotating moment of inertia and I1, means the total 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

Introduction The 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.

Objectives 1.Determine the Young' Module by metal wire 2.Determine the Young' Module by deflection of a beam 3.Determine the length and thickness by caliper gauge and micrometer Experiment--- Determine the Young' Module by metal wire To estimate the Young's Module of material, tension method and beamdeflection 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.

F

external force (N) L the elongation of bar (m) L the length of bar (m) d the diameter of bar (m) L0 initial length of bar (m) S cross section area of wire (m2)

Steel wire 80.9 F(N) 848 L0(mm) 851.13 L(mm) 3.13 L(mm) 0.37 D(mm) 2 20.4 Y(dyne/cm )

Experiment--Determine the Young' Module by Deflection of a Beam Secondly 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.

Y: Young Modulus H: central deflection of beam F: driving force L: the length of beam between both supports B: the width of beam t : the thickness of beam F

Steel bar 27.5 F(N) 8.36 H(mm) L(mm) 139.56 B(mm) 22.97 t(mm) 0.75 2 Y(dyne/cm ) 23.1

H

L0 F

F

L

07

Introduction it 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.

Here Vi is the local velocity flowing across the corresponding diameter Di of pipe cross-aera Ai with liquid elevation

hi and Q means

volumetric flow rate.

Objectives 1. 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.

1

2

3

4

5

6

D1

D2

D3

D4

D5

D6

Experiment ---Venturi Tube The 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.

09

Introduction With 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, substancewave behavior for ripple experience on the water pool is designed and experimented.

Objectives In this subject, the water tank experiments are intended to produce different wave pattern depending on various geometry of actuator. Relevant rippleexperiment listed below will be surveyed.

7.reflection mirrors 4.wave's refraction 1.point wave 8.refractive lens 5.wave's diffraction 2.straight wave 9.Doppler effect 6.wave's interference 3.wave's reflection

Features 1.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.

10

Introduction

Experiment---Standing wave in closed pipe

To 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.

This 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

N B

C A

A

N

A

formation and characteristic.

: pipe-lenghth

No. of wave node freq. f (Hz) experiment (cm) theory

(cm) relative error (%)

N E

/2

preasure node preasure antinode

average Standing antinode

Standing node

Objectives

400

Wavelength(cm)

1.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 resonanceformations for open and closed pipe will be investigated.

350 300 250 200

Experimental values

150

Theoretical values

closed pipe

100 50 0 0

1

2

3

4

5

6

7

8

open pipe

Wavenumber n

12

Introduction

Experiment---Boyle's law

To 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.

Through 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: pV k

Objectives 1.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 powercycle 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.

Pressure (kPa)

25 b 20 15 10 a 05 00 -20 00 20

2012 3 26

09:27:46

Carnot cycle

c

d 40

60

80

100 120 140 160 180

Pulley 11mm (mm)

Pressure (kPa)

50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0

Boyle's law

y=-0.001x+47.401 r2=0.998

0

5000 10000 15000 20000 25000 30000 35000 volume (mm3)

Experiment---Charles and Gay-Lussac's law Through 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. V bT

Temperature ( ) Charle's law 80.0 70.0 60.0 50.0 40.0 30.0 20.0 y=0.002x+17.982 r2=0.991 10.0 0.0 0 5000 10000 15000 20000 25000 30000 35000 40000 volume (mm3)

14

Introduction

Experiment---Colors mixing and propagation

As 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.

Experiment---The measurement of lens focus

Objectives 1.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.

Features 1.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.

Experiment---Single slit diffraction As 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 of central bright line yc and the spacing dark line yd might be yielded below.

yc

2

L a

yd

L a 15

The 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.

Objectives Malus' Law of Polarization Brewster's angle

Experiment---Law of Malus As 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.

Intansity(mW)

Introduction

Angle(degree)

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, 1 , called Brewster's angle at which the reflected ray and the refracted ray are 90 degrees apart and the light energy parallel to reflected plane will disappear. incident ray (unpolarised)

Reflected ray (polarised)

Refracted ray (slightly polarised)

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 s-polarized disappear. unpolarized

p-polarized

16

Introduction

Experiment---polarization and Brewster's angle

Similar 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.

I

(0 ) (90 )

i ~56

Experiment---Michelson interference

Objectives 1.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---Double Slit Interference

Experiment---Bragg Diffraction

dsin

dsin

d

17

Introduction

Experiment---Ohm's Law

Just 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

As the voltage V is subjected to both ends of a conductor, the current I, inversely proportional to the resistance R, will be induced. That means V = IR 9 8 7 6 5 4 3 2 1 0

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Objectives

Features 1.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---the properties of diodes measurement This 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.

ID(mA)

1.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.

180 160 140 120 100 80 60 40 20 0 0

0.2

0.4

0.6

0.8

1 VD(V)

18

Introduction

Objectives

Base 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.

1. Parallel plate capacitor 2. Two points within a field 3. Point and plane 4. The lighting rod

+Q

reference position

A

+

Measuring position

Experiment results

Q

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.

19

Introduction

Experiment---Tangent Galvanometer

In1820, an electromagnetic theory was initiated by Oersted. Here the

With rotating angle of magnetic pin measured, axial magnetic field induced from solenoid Baxis could be determined.

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

N=15 Baxis Current(A) Angle( )

amounted

H

0.500

51.5

4.620E-05 0.367491

the current induced along the closed loop while a time varying magnetic

1.005

66.5

9.286E-05 0.403775

flux, across the sectional area of coils, is undertaken. That also explains

1.495

74.0

1.381E-04 0.396103

2.000

78.5

1.848E-04 0.375979

the mutual relation between electric current and magnetic field, and has become a fundamental principle for electromagnetic application in our

Experiment---Current Balance

daily life. Base on quantity analysis from theoretic or empirical model,

Apparent weight on the load cell, experiment of Lorentz force, could be induced by a current carried by two parallel magnets.

the experimental kits, in this subject, also provides some interesting demo related to electromagnetic demonstration.

Objectives 1.Geomagnetic measurement : Tangent Galvanometer

Experiment---Faraday's law

Determination by the magnetic moment

If 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.

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

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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.

Objectives

Experiment---RLC

1. Investigate the time constant for value of C in charging or

A fundamental RLC series circuit, figured right, is primarily constituted Vs 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

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

R

L

C

will be also available to the fluctuated frequency

charging or discharging process, the needed value of capacitor might be determined.

Charge (discharge)circuit diagram

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 , defined as the ratio

n Charge on capacitor vs. time duration

Discharge from capacitor vs. time duration

of terminal voltage and power supplied voltage, might be estimated on the profile sketched below.

Resonant response of voltage vs., time duration

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h Rather 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

Incident light

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 V0 is just adequate to break through the barrier. Thus planck's constant h might be determined from the equivalence of energy emitted from laser diode, hf, and power absorption of photon e ( V-V0).

diffracted light Reflecting Grating

100 x Diffraction Angle (Rad)

Introduction

Incident Grazing Angle (Rad)

Experiment---V-I characteristic of diode laser Base 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).

Objectives 1. 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 diffraction

Linear Regression

Base on the pattern of interference fringes reflected from the multigratings on steel straightedge, the wavelength of laser might be determined. Here the bright fringes occurs at =dCos

-dCos(

+

n )=n

where f= vc/

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Introduction

Intensity

In general, light spectrum could be classified into discrete spectrum

3

2

1

m=0

1

2

3

1

2

3

and continuous spectrum. However, both absorption and emission are the main typical pattern for discrete spectrum. Unlike the discrete way

0 (a)

mentioned above, typical continuous spectrum, in this experiment, will be investigated. Here a slice with 500line / mm grate will be used to 3

observe the spectrum from incandescent lamps, sunlight and candles (experimental mechanism as shown in Fig.1). While the below condition

2

1

m=0 (b)

Fig.2 The plot of intensity for bright fringe

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

Objectives 1.Observation of continuous spectrum from incandescent lamp 2.Determination the wavelength of emission spectrum from fluorescent lamp

line and the distance from light source to grating.

Experiment--Wavelength spectrum of mercury-containing fluorescent

2

Deep Purple

Purple

Aquamarine

Green

Yellow

S

Red

Red

Light source

screen

4 3

6 5

1 eye

Fig.1 Diffraction of grating light with wavelength

7028 6908 6714

2 6234 6124 6073 5791

8 7

4964 4358 5461 4916

4047 4078

( )

5770

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