OR and NOT gate

AND and OR gate

OR and NOR gate

AND and NOT gate

Oil

Grease

Electrolyte gel

Petroleum jelly

Carbon

Insulator

Conductor

Semi conductor

1/R = 1/R1 + 1/R2

1/R = 1/R1 ? 1/R2

R = R1 + R2

R = R1 ? R2

Less current

Varying current

Excess current

Rated current