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Physics Investigatory Project for class 12 cbse is a mandate for class 12 cbse students.

Across the Universe

The objective of this investigation is to scientifically be able to calculate the constant velocity, one at which a human being who is in a spaceship would need to travel in order to go from the earth to that portion of the universe that is visible from Earth. That distance which is about 13.7 billion light-years away.

Method of doing this investigation

You would need

  • Pencil
  • Sheet of paper
  • Scientific calculator
  • The Cosmic Perspective – A textbook on Astronomy.

Apply the time dilation formula of special relativity that you shall find in the book The Cosmic Perspective and calculate how fast a person would have to go in order to travel 13.7 billion light years which in their relative time they would perceive as one day.

The figure that you arrive at is the distance from Earth to the edge of Earths visible universe, which is the portion of the universe that an observer on Earth could possibly observe.


Thus, to be able to travel 13.7 billion light years in one day, a person would have to go at approximately the square root of (1- 10^-26)multiplied by the speed of light.

You would need to keep the number in radical form, because the number under the radical sign is very close to 1, and seeing as the square root of 1 is 1, the square root of a number that is close to 1 is going to be even closer to 1, so it is more convenient to leave the number in radical form.

This investigative experiment shows that through massive objects cannot match the speed of light or go faster, it is not impossible to travel large distances in very short amounts of time. Keep in mind that an object travels at a faster and faster pace, its relative passage of time becomes slower compared to the passage of time of an object that is not moving, and so, therefore, it can travel across distances that are great in short amounts of time. You could say that this is a form of non-instantaneous time travel.

Cold Nuclear Fusion

This experiment is conducted to see if an alternate energy source can be created using a cold nuclear fusion reaction. You need to conduct a cold fusion experiment that is similar to one conducted by Drs. Fleischmann and Pons. If the experiment proves successful then cold nuclear fusion could provide a nearly limitless energy source.

This experiment was conducted with the help of just water. With just water, the scientists speculated that the cold fusion reactors could take the top ten feet of Lake Michigan and use it to generate enough power for the whole United States for 1500 years.


You need to experiment with several variations of water. Let’s take deuterium oxide (D2O). You will need to transfer the D20 to a jar and insert a thermometer as well as two electrodes (platinum anode, palladium cathode)which are connected to a power supply.

Pass electricity through the D20, This will break down into deuterium and oxygen.

The atoms are ionized by electrons and move to the electrode opposite their charge.

The oxygen that is negatively charged moves to the positive anode, while positively charged deuterium moves to the negative cathode.

If the experiment is successful, the deuterium will be concentrated in the palladium.

This concentration of the D20 will be very high and be enough for the nuclei to touch, causing the deuterium atoms to bond with one another and in the process forming helium. In addition, this process will release energy in the form of heat.


Do the test doing a variation of water. Use regular water, sea water and D2O. You will see there is a difference in the conclusions.

In the case of  D2O, the temperature shall rise 1 degree (F) only. The current that is flowing through the solution will fluctuate. Burn the collected gas, you will see that the stable helium has not been produced. These factors indicate that no fusion reaction occurred.

Using Sound to Measure Temperature

To be able to find out the temperature of air which is inside a pipe by measuring the speed of sound.


You will need

  • Microphone,
  • speaker,
  • oscilloscope,
  • audio generator,
  • thermometer,
  • hairdryer,
  • 6 (3 ft and 7 in) foot pipe.

Place the speaker and microphone at each end of the pipe. You need to measure the length of the pipe, which will be the distance between the speaker and the microphone.

Combine the equations: v (sound) =331+0.6T and v=d/t, where d=1.1 meters, and T= temperature in degree Celsius. These two equations would combine to create d/t=331+0.6T by the means of this equation, you can find out the lag time between the speaker input and output for the temperatures from 0 to 100 degrees Celsius,

Thereafter, you need to calculate the time that is taken by sound to travel through the pipe at 0(C), and the time taken by sound to travel through the container at 100(C), and subtract them.

After which you need to divide this number by a hundred. ·

To further the experiment, use a hair dryer and heat the air in the pipe to the desired temperature and turn on the sound waves.

Once done, you will need to mark the intersection of the wave that is on the oscilloscope grid immediately before and after the hairdryer has been used. This will indicate the lag time.

Now, for every 5 microseconds of lag, add one degree Celsius. ·

Calculate the temperature, and compare the number with the thermometer. · Let the pipe cool down and then repeat the procedure

It is concluded that you can predict the temperature accurately by the velocity of the sound that passed through it. When the temperature was increased, the speed increased; and when the air slowly cooled, the speed decreased.

To know more about Ray Optics, click here

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