6. Potentiometer

It is a potential divider. It consists of a continues resistance wire with a divider. When we move divider with the help of knob the resistance about both sides of divider varies. Correspondingly, the voltage varies from 0 to 5V across one side of divider. The middle wire is correspond to the divider. Other 2 wires are connected to Vcc (5V) and Ground (0V). We will use POT of 10K, i.e., its maximum resistance is 10K.

Full form of LDR is Light Dependent Resistance. When light falls on it, its resistance decreases and voltage across it decreases. Mechanism behind this is that when light falls on it, electrons are emitted so that current increases and resistance decreases.

8. LED


Its full form is Light Emitting Diode. The current applied to it should be low so that we always connect a 100 ohm resistance in series with it. It has 2 legs. Longer leg is always connected to Vcc (5V) and shorter leg to Gnd (0V).

We use two 6V dc motors to run our robot.

 We use 9V battery.

11. Carbon Resistances



We will use 100 ohm resistances and 10K ohm resistances. Carbon resistances consists of 4 coloured lines representing its resistance. We can measure its resistance by colour code or multimeter.
12. Four pin connectors

Connectors are used to fix 1 LED and 1 LDR in a pair. 13. Wire cutter It is used to cut the wires. 14. Multimeter                It is used to measure the resistance value, potential differences, connectivity and current flowing in the circuit. 15. Connecting wires The wires should be thick and hard so that it properly connects with the breadboard. It contains a single aluminium wire coated with plastic.