An EX-OR gate can only have two inputs. The output of an EX-OR gate is true when its inputs are different (one true, one false).
Relay An electrically operated switch, for example a 9V battery circuit connected to the coil can switch an AC mains circuit. The rectangle represents the coil. NO = Normally Open, COM = Common, NC = Normally Closed.
Aerial (Antenna) A device to receive or transmit radio signals. It is also known as an antenna.
A NAND gate can have two or more inputs. The o on the output means not showing that it is a Not AND gate. The output of a NAND gate is true unless all its inputs are true.