What is the difference between resistive, Inductive, motor, and lamp loads ?

We must express the load as a contact rating, which is the electrical load-handling capability of relay contacts under specified conditions and for a prescribed number of operations or life cycles.

RESISTIVE LOAD : A resistive load usually consists of some sort of resistance in the circuit: e.g. heaters, resistors, etc.

INDUCTIVE LOAD : An inductive load consists of a load created by a wire wound coll, such as in a relay or solenoid, a transformer, or any load which uses a winding over a magnetic iron core. Breaking an inductive load is usually more severe than breaking a resistive load and will generally produce heavy arcing.

MOTOR LOAD : A motor load can be referred to as a rotating inductive load, generally with a high inrush of six times the normal load. The breaking of the load is much the same as a resistive load.

LAMP LOAD : There are many types of lamp loads such as tungsten filament, fluorescent, mercury-vapor, and other exotic gas lamps. The loads we normally concern ourselves with are tungsten filament. Tungsten filament lamps, when first turned on, will draw an inrush current of 10-15 times of the steady-state current. The inrush is similar to a motor load inrush and is caused by the cold filament in the lamp. After the lamp filament has heated up, the current will drop to its normal level. Most tungsten filament lamp load ratings are 20% of a resistive load.