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RAGGING-CAN BE GIVEN A MORE POSITIVE DIRECTION
posted on 02 May 2009
by:anshu chaudhry
PARENTS MUST HAVE REALISTIC EXPECTIONS
posted on 02 May 2009
by:anshu chaudhry
SOCIALISATION -THE FOUNDATION 0F HUMAN LIFE
posted on 29 Apr 2009
by:lalit kumar
CBSE Multimedia Animated CD DVD : Free Delivery Dial 01164614067
posted on 28 Mar 2009
by:TopRank India
JUST PASS IT ON..........
posted on 24 Mar 2009
by:anshu chaudhry
SHARING-THE BEST WAY TO GO!
posted on 24 Mar 2009
by:anshu chaudhry
OBESITY ON THE RISE IN CHILDREN
posted on 24 Mar 2009
by:anshu chaudhry
INSTILL HEALTHY EATING HABITS IN YOUR CHILDREN
posted on 24 Mar 2009
by:anshu chaudhry
Schoolsonweb
posted on 20 Feb 2009
by:Poo
DEALING WITH MOOD SWINGS!!!:-(
posted on 15 Feb 2009
by:priyannkaa dey
 
Featured Experiments
1 Relations between Simple Harmonic Motion and Circular Motion
Here we show the relationship between Simple Harmonic Motion and Circular Motion
2 Traffic Control System
Would you like to engineer the traffic light system for a one-way street that consists of several lanes along which rush-hour traffic flows?

How would you time the onset of green lights at the various intersection?
How to promote the traffic flow? This experiment lets you play with it.

You can click the +/- sign to change the time delay between traffic lights.

How to use this experiment

  1. The traffic lights at interactions are for cars moving from left to right. The traffic on the perpendicular streets can only move when light is RED.

  2. You can change the period of each light

    1. Clicking the traffic light at the top-left corner
    2. The number near each color is the period for that particular light (second)
    3. Left/Right mouse click will decrease/increase one second
    4. ( for MAC user, click between light and number to the right to increase the length of time)

  3. Parameter controls: Each click to the arrow at left/right of the number will decrease/increase
    the parameter by 1 unit.

    1. Delay time control: near the traffic light controls the delay of the onset of green light at the interaction relative to that at previous intersection.
    2. Max Velocity control: represents the speed limit  ¡]Vmin=5, Vmax= 50¡^
    3. Acceleration control: represents the acceleration for the car when it speeds up. ¡]Amin=1 , Amax=20¡^

  4. Text Field values

    1. T¡G time in second after pressing the start button
    2. N1/N2/flow rate¡G total number of cars passes intersection (N1:left-right/N2:up-down)
      flow rate=(N1+N2/3.)/T
    3. n1/n2/flow rate¡G number of cars passes intersection during last minute.
      flow rate=(n1+n2/3.)/60


  5. Color code for car
    1. yellow: accelerating (A>0.)
    2. green: moving with constant speed (include stopped) A=0.
    3. red: stopping (A<0.)


  6. Velocity of each car is represented by a blue dot.

  7. A new function has been added to help you determine the delay time between traffic lights.
    Click the right mouse button to suspend (the animation).
    The time intervals (for the first car ) during which the signals are green/yellow/red
      are represented by thin (colored)lines at one side of the road.

  8. A blue curve represent x-t (displacement verse time) for the first car is shown.
    Use that curve with those color intervals to adjust the delay time between
    traffic lights. Click the right mouse button again to resume.

Observation:

  1. Suppose a platoon is stopped at interaction. When the green light comes on, there is a "start-up wave" travels from the leader along the length of the platoon at a speed vs.
  2. How to adjust parameters to increase the traffic flow?
    1. adjust timing of each light
    2. adjust delay time control
    3. adjust Vmax
    4. adjust A(acceleration)
3 Heat transfer
Heat transfer between metals and water experiment. Placing a hot piece of metal in water in a calorimeter.
4 Boiling & Freezing Point
Here you will learn about boiling-point elevation and freezing-point depression
5 Effusion Micromolecular
6 pH Measurements: Salts & Buffers
7 Electrochemical Cell- Electrolysis
8 Transmission line calculator

This is a little transmission line calculator applet. A number of the ideas were borrowed from TL.EXE by Dean Straw N6BV. The values of the built in cable attenuations were taken from that program.




To use this applet, change the values in the input fields, and click calculate. Most of the fields should be self explanatory but I'll elaborate a little more below.










To interrupt a calculation in progress, click stop.




The cable type is a menu of common cable types that can be used. In addition two user defined entries allow you to enter custom cable types as described below.




You need to enter the frequency in the first text field. The label "Cable Length in Feet" can be changed to "Cable Length in Meters" which will change all the length units from feet to meters. You then enter the length in the cable length field. Similarly, the "Load Resistance" label can be changed to "Input Resistance" so that measured impedances at the input end of a cable can be converted to antenna impedances. Enter the resistance and reactance (positive for inductive, negative for capacitive) in those fields.




When your input is set, press calculate. If there is an input error a message will be displayed in the field to the left of the stop button. The output side only changes when you press calculate, and will display the characteristic impedance Z0 of the line, the impedance at the other end of the line, the velocity factor, the SWR at each end of the line, the matched loss of the line, and the total loss with your load impedance.




The bottom part of the applet is a plot. The x axis is the position along the line; x=0 is the input. The default shows the power, current and voltage on the line all on one plot. To make them all appear on a single plot, I take the current to have magnitude one at the load, I divide the voltage by the characteristic resistance of the line, and I divide the power by its value at the load. At the top of the plot is a choice menu that allows you to also select the power in watts, voltage magnitude in volts, or current magnitude in amps with 1500 watts input to the line. You can also plot the impedance in ohms seen along the line. The red curve is the resistance and the blue one is the reactance. One of the nice features of this package is that you can zoom in on a portion of the plot by holding down the left mouse button on that portion and move down and to the right to highlight the region with a little square. You can do this multiple times too. If you hold down the left mouse button and move up and to the left, you can unzoom. The easiest way to get back to the original is to click calculate again.




Two user defined cable types are provided. For user 1, you enter the resistive part of the characteristic impedance, the velocity factor and the attenuation in dB/100ft at some frequency. If you want to extrapolate to other frequencies, the exponent would be exactly 0.5 if the loss mechanism were purely conductor losses, and that should be good enough for a first guess. Otherwise, the loss at a new frequency will be the ratio of the new frequency to this frequency raised to the exponent power times this attenuation. The reactive part of the characteristic impedance is calculated assuming only conductor losses.




User 2 does not scale the results with frequency. Instead you input the characteristic impedance both resistive and reactive parts, the attenuation and the velocity factor. These characteristics are assumed to not change with frequency.

9 Space Ship Control Under Gravitation Field
There are two space ships in circular motion (under the same gravitation field/same speed).
Suppose you can control the second space ship. You can click the button to change the velocity (in forward/backward/left/right) directions.
Each click will change the same amount of speed dv (dv can be change by slider).
Default dv=2.5 and you can fire the button 10 times.
If you double dv, then you can only fire 5 times. (If you reduced dv to half, then you can fire 20 times).
10 Electric field structure and Field lines for two point charges +/-
Drag either charge and find out the new electric distribution.

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