Nowadays, an electronic device - the cell phone - is very popular. From a mobile shop near your house, find out how they dispose off old and broken down cell phones.

Where does the signal in your cell phone come from?

Where does the signal in your cell phone come from ?

How does a cell phone charger produce a voltage of 5V from the line voltage of 230V?

Where does the signal in your cell phone come from? Where from does it come to mobile towers? Where does the signal to your TV set come from ? Youb may have seen photographs showing the position of monsoon clouds over the contry, in the newspaper. How are these images obtained ?

An 'app' may be available on cell-phones to measure the loudness of sound in decibel. With the help of your teacher, use the app to measure the sound level of a sound from a loudspeaker at some public place. Measure the sound level at different distances from the loudspeaker. Do you observe some relation between the distance from the loudspeaker and sound level?

Figure shows a potentiometer with a cell of 2.0 V and internal resistance 0.40 Omega maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02V (for very moderate currents upto a few mA) gives a balance point at 67.3 cm length of the wire.To ensure that very low current drawn from the standard cell,a very high resistance of 600 k Omega is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf E and the balance point found similarly,turns out to be at 82.3 cm length of the wire . Would the circuit work well for determining an extremely small emf, say of the order of a few m V (such as the typical emf of a thermo-couple) ? If not , how will you modify the circuit ?

Find out the correlation: Radiations from cell phones: Headache::………..:Hindrance to the brain development.