The mosfet is off if the input voltage is normally less than \(2.0 V\). By looking at a circuit diagram of a transistor switching circuit, you should be able to say what the circuit is used for ...

Often, they are supplemented by additional components like crystals and oscillators, electromechanical components like relays and switches, and connectors ... A special type of component is the ...

To turn out the light we need to break the circuit. We can do this by putting in a switch. It doesn't matter where in the circuit you put the switch - the effect is the same. The bulb glows ...