Update README.md

1-getting-started/lessons/3-sensors-and-actuators/README.md

@@ -54,7 +54,7 @@ Sensors are either analog or digital.
 
 Some of the most basic sensors are analog sensors. These sensors receive a voltage from the IoT device, the sensor components adjust this voltage, and the voltage that is returned from the sensor is measured to give the sensor value.
 
-> 🎓 Voltage is a measure of how much push there is to move electricity from one place to another, such as from a positive terminal of a battery to the negative terminal. For example, a standard AA battery is 1.5V (V is the symbol for volts), and can push electricity with the force of 1.5V from it's positive terminal to its negative terminal. Different electrical hardware requires different voltages to work, for example a LED can light with between 2-3V, but a 100W filament lightbulb would need 240V. You can read more about voltage on the [Voltage page on Wikipedia](https://wikipedia.org/wiki/Voltage).
+> 🎓 Voltage is a measure of how much push there is to move electricity from one place to another, such as from a positive terminal of a battery to the negative terminal. For example, a standard AA battery is 1.5V (V is the symbol for volts), and can push electricity with the force of 1.5V from it's positive terminal to its negative terminal. Different electrical hardware requires different voltages to work, for example an LED can light with between 2-3V, but a 100W filament lightbulb would need 240V. You can read more about voltage on the [Voltage page on Wikipedia](https://wikipedia.org/wiki/Voltage).
 
 One example of this is a potentiometer. This is a dial that you can rotate between two positions and the sensor measures the rotation.