Final answer:
The basic electrode among the listed options is b) E4914. Basic electrodes contain calcium compounds and are known for their crack-resistance and producing cleaner welds with good mechanical properties.
Step-by-step explanation:
The electrode classified as a basic electrode is b) E4914.
Electrodes in welding are categorized based on the composition of the coating applied to them. Basic electrodes, which are also known as low-hydrogen or lime-titania type electrodes, contain calcium compounds (like calcium fluoride) that produce a basic and are designed to weld cleaned and prepared workpieces with minimal moisture content in the coating. This is opposed to cellulosic electrodes (a) E-6010 or electrodes containing titania, which have different properties and uses. Basic electrodes are used for their crack-resistance and for cleaner welds with good mechanical properties.
E-6010 would be classified as a cellulosic electrode due to its high cellulose content in the coating, which produces a deeper penetrating arc and is suited for welding on dirty or rusty metals. On the other hand, titania electrodes (like E4916) often contain a considerable amount of titanium dioxide, which stabilizes the arc but does not necessarily classify them as basic electrodes.