Lab in your pocket जेब में प्रयोगशाला
Your phone has an accelerometer, gyroscope, microphone, magnetometer and camera. Use them for real Class 9–10 practicals. Permission is asked only when you tap start, and every experiment has a simulated demo if your phone lacks a sensor.
Measure g with a pendulum लोलक से g मापें
Class 9 · Gravitation. Your phone becomes the pendulum bob and counts its own swings.
- Tie the phone firmly in a cloth pouch or rubber band to a 0.5–1.5 m string.
- Tap start. You get 5 s to hang it and pull it aside a little (under 10°).
- Let go at the beep. Don’t push. It stops by itself.
| S. No. | L (m) | Oscillations n | Time t (s) | T = t/n (s) | g (m/s²) | Method |
|---|---|---|---|---|---|---|
| No readings yet. Take one above. | ||||||
How does the phone count swings?
The gyroscope measures how fast the phone is turning. As a pendulum swings, this turning speed goes from positive to negative and back once every period. The app smooths the signal, counts how often it crosses zero (twice per oscillation) and divides the time by the number of oscillations to get T. If there is no gyroscope it uses the accelerometer, whose reading peaks at the bottom of every half swing. Then g = 4π²L/T².
Lab notebook प्रयोगशाला नोटबुक
Saved only in this tab’s memory. Nothing is uploaded; closing the page clears it.
Your saved readings from every experiment appear here.
Common questions
How can a phone measure g?
Hang the phone as the bob of a pendulum. Its gyroscope senses the swing, the app counts oscillations to find the time period T, and calculates g = 4π²L/T² from the length L you enter. Most students get within a few percent of 9.8 m/s².
Is the sound level in decibels accurate?
Phone microphones are not calibrated, so treat the dB number as a guide for comparing sounds. The frequency (Hz) reading is accurate to a few hertz for steady sounds.
Why does the compass not show μT on my phone?
Some browsers share only the compass direction and not the raw magnetometer values. You will still see the heading; the simulated demo shows how field strength changes near a magnet.
Can the pulse experiment check my heart health?
No. It is a science demonstration of how light and blood flow reveal a heartbeat. It can be wrong and must not be used for medical decisions.
Is any of my data saved or uploaded?
No. Readings stay in the page’s memory only. Camera frames and microphone audio are analysed on your phone and immediately discarded.