Home Contact Us
About Us Institutes Classrooms Forums Blogs V-Lab Contents

vlab

User ID :
Password :

Forgot Passsword ?  |   Join Us

Click Here For Login

more

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 Magnetic field pattern for (line/ coil/ solenoid)
You will find magnetic field pattern for a current flow in a vertical wire.
Press "play", the wire will become a circular current loop.
When it "paused" again, press "play" again. And it will wound in the form of a helix. (solenoid)
You can change the Radius R or change the Z-plane to view field distribution at different Z value.
The popup window shows the magnetic flux distribution.
2 A rod supported by two spring on both ends
You can change the spring constant of each spring.
Drag center of the rod  to change its location. drag end of the rod to change the tilt angle.
Enjoy the fun of modeling motion of the rod.
3 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.

4 Two blocks with mass m1,m2 connected by a spring with spring constant k2.Two blocks connected with spring with external force push
Two blocks with mass m1,m2 connected by a spring with spring constant k2.
Drag "hand" in the simulation to push or pull the system (with spring k1) and watch how the system moves.
5 Boiling & Freezing Point
Here you will learn about boiling-point elevation and freezing-point depression
6 Particulate nature of matter
Find out about the view of a metal at different temperatures
7 A ball climb up another object on a frictionless surface
Because there is no friction between objects and between object and the ground.
The total momentum in the horizontal direction must be conserved.
Try with different initial velocity and water how the motion changed!
The total energy of the system is always conserved,too!
8 Atomic Spectra of Hydrogen and red shift
This applet shows you atomic spectra of hydrogen.



The wavelengths of hydrogen spectra lines can be described by the following equation:



1/λ=RH*(1/n12-1/n22)

where RH=1.0973732*107 m-1



You can change n1 with the slider bar. The program will plot a series of spectrum lines.

You might want to change the xmax(at the right) to see the full range of the spectra.

One of the line is thicker and with an arrow is the one with n2 equal to slider bar value.



Click within simulation region will toggle "visible spectra range".



You can also find out how the red shift of the spectra calculated from Hubble's law.

v=H0 D where the recessional velocity is proportional to the distance of the star to the earth (D). You can adjust the distance of the star.

And see the red shift of the hydrogen spectra from that star due to the expansion of the universe.





n1=1 NULL series (Ultraviolet)

n1=2 NULL series (Near Ultraviolet and Visible)

n1=3 NULL series (Infrared)

n1=4 NULL series (Infrared)

n1=5 NULL series (Infrared)
9 Particle Model for Solid/Liquid/Gas States in 3D
Matter can be either in solid,liquid or gas state due to the change in temperature.
This is an animation of 3D particle model for such situation.
Because we need to add enough particles and calculated all the interactions between any two particles. the animation is a slow motion to illustrate a real situation.

The color for the particle is varying according to the Z coordinate (to help you see the whole structure more easily)
You can change the gravity and Temperature of the system.
You can also drag the slide on the right (up and down) to see the locations for particles at the selected Z position. (shown in gray at the top:zmax)
The following image shows particles in solid state and form a fix structure. Because of the gravity, there are more particle near the bottom of the container.




If there is no gravity, you will find something similar to the followong

10 Water eject from a hole in a water tank
If there is a hole in a water tank, water will shot out due to water pressure.



You can drag the hole up and down to change its position.

Copyright 2007 www.MeraCollege.com | Terms & Conditions | Privacy Policy