Some common circuit symbols are shown below:

Common Circuit Symbols
connecting wires
joined wires
wires crossing (no contact)
cell
battery
a.c. supply
resistor
variable resistor (rheostat)
heat-dependent resistor (thermistor)
light-dependent resistor (LDR)
ammeter
voltmeter
galvanometer
centre-zero galvanometer
bulb
switch
earth connection
fuse
diode
light-emitting diode (LED)
electric bell
buzzer
motor
transformer (with iron core)