11P09D Surface Tension / Mechanical Properties of Fluids
Why Soap Bubbles, Liquid Drops take Spherical Shape ? Soap Film taking minimum Area.
Surface Tension is one topic that is slightly difficult for the students. Simple home experiments can help to grasp the idea.
Students Shreya and Jagan Surface Tension Experiments
If you have access to a microwave oven, see if you can do this simple 10 minutes experiment in your microwave.
1. Remove the turn table inside the oven
2. Place an uncooked Chappathi (Tortila) or similar flour item spread out
3. Switch on the oven for a nominal time ( may be 1 minute or 2 minutes as required)
4. Open the oven and look for any black spots where the heat is concentrated
5. Measure the distance between the black spots using a measuring scale (few cm expected)
6. In the instrument label in the back side of oven look for any frequency of microwaves used.
7. We are looking for the Speed of Microwave c = Frequency x Lambda, calculations from the above values obtained.
8. Any videos or pictures of the experiment will be very helpful for educational purpose may be to upload in youtube.
Microwave is an Electromagnetic wave. All EM waves such as light, radio wave, microwave, infrared wave, uv rays, x rays, gamma rays travel at the speed of light c = 3 x 108 m/s. This experiment is an attempt to experimentally verify the speed of microwaves.
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| Before Heating |
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| After Heating, approx.6 cm gap between black spots |
11P04 Newton's Laws of Motion
Student Swetha's Apparent Weight Experiments in Lift
(Class 11 student 2023-24)
Actual reading before getting on the lift: 50 kg shown.
This is approx. 500 N due to gravity alone. Fg = mg = (50) (10) = 500 N.
12P10 Wave Optics: Student Hashmitha's Experiments
(Class 12 student 2023-24)
Young's Double Slit Experiment YDSE: Small slits made in an aluminium foil and Laser light used here to get the bright and dark fringes.