Hobs and Cooktops
Cooktops and hobs are usually between 600 and 900mm wide and with four or five heating zones or burners. Usually the heating zones or burners are arranged by heat output so there will be large, medium, simmer zones and with gas hobs, sometimes a wok burner and even a fish burner on larger hobs. Cooktops and hobs are recessed into the benchtop so that only the edge of the unit stands proud of the surface. Domino hobs get their name from their oblong shape and have one burner at each end. These may be mix-and-matched on a benchtop to provide a mixture of gas and electric cooking. They are commonly found in motels and small apartments but also add versatility in the kitchen by supplementing a 600mm cooktop.
Gas hobs
Gas is popular because the heat is visible, easy to control, and cheaper to use than electricity. Most now have mains powered ignition rather than the piezo devices in older models. Most also feature the flame failure device, which switches off the gas flow when the flame is blown out. Unfortunately, popular though this device has proved to be, it does tend to be the one thing that occasionally fails on an otherwise very reliable appliance.
EGO Hobs
EGO hobs feature electric sealed plates where an iron plate is heated to provide heat for the pans. They give a traditional look and are are efficient at providing an even heat distribution across the base of the pan. Look out for hotplates with a red spot. This indicates extra power for quicker warm-up so some hobs will have two plates with red spot and two without, indicating which plates to use for simmering and which for a quick boil or for frying.
Ceramic hobs
Ceramic cooktops are popular for the clear, uncluttered surface they present and for the easy-wipe cleaning. The have a toughened glass surface with heating elements beneath from which the heat is conducted through the glass and onto the base of the pan. They are easy to clean provided that sugary spills are not allowed to bake on for any length of time. Some ceramic cooktops have control knobs but increasingly popular are those with soft-touch controls, which present a completely clear surface.
To work properly ceramic cooktops require pots and pans with completely flat and preferably solid bottoms. If the pan bases don't make 100% contact with the surface of the cooktop, heat will not be transferred to the pan effectively causing pan to not heat up properly and the appliance to cycle. That is it will switch on and off repeatedly to prevent the appliance from overheating.
Induction hobs
Induction cooktops are similar in appearance to ordinary ceramic ones because the feature the same type of surface plate. However, the way they provide heat to the pots and pans is completely different. Induction cooking is the process of heating an electrically conducting object by electromagnetic induction, where eddy currents (also called Foucault currents) are generated within the metal and resistance leads to Joule heating of the metal. Since the process is magnetic it requires ferrous pots and pans, that is steel or iron. Aluminium, ceramic or copper, will not work.